最高の SMTP ホスティング サービス (2026) – トップ 12 比較 - JA

今 -81%

1. SiteGround

4.6

Number of Reviews 29.1k +

Avg. Review Rating 4.8 ポジティブ

Customer Support ポジティブ

Starts from $3.41 / mo.

Server Locations

plans

View this deal

Read full review

SiteGround – Best bundled SMTP for small sites

エントリ: 2.99ドル/月. リニューアル: 17.99ドル/月. Outbound cap: 400 メール/時間 (起動).

Four hundred emails an hour. That is the StartUp ceiling, and it tells you exactly who SiteGround's bundled mail is for: お問い合わせフォーム, order notices, the occasional newsletter to a short list. Move up to GoGeek and the cap doubles to 800 an hour. You can put up to 80 recipients on a single message, but each one counts against that hourly quota. One big send eats it fast. SiteGround runs this on Google Cloud, and its own acceptable-use docs are blunt that the mail service is for "standard communication," not campaigns. Push real marketing volume and you get steered to its separate paid Email Marketing add-on.

For sending headroom, that 400/hour floor is 60% more than InMotion's 250/hour and roughly four times GreenGeeks' 100/hour. It still trails any dedicated relay by a mile: SMTP2GO's free tier alone clears transactional bursts a shared host would throttle. The renewal is the part that bites. You sign at USD 2.99 and re-up at USD 17.99 月, so treat the first-year price as a trial rate. The web-host context here is covered more fully in our shared hosting roundup if you want plan-by-plan detail.

• Scales sending by plan: 400 に 800 メール/時間
• Google Cloud infrastructure with SPF and DKIM in Site Tools
• 30-当日返金窓口
• Four data center regions (私たち, イギリス, オランダ, シンガポール)

• 更新は次へジャンプします 17.99ドル/月 米ドルから 2.99
• Every recipient counts toward the hourly cap
• Bulk and marketing email pushed to a separate paid product

こんな方に最適: a brochure or small WordPress site that sends a few hundred emails a day. 次の場合はスキップします: you send transactional email at any real scale, where a relay like ZeptoMail or SMTP2GO belongs.

評決: Choose SiteGround when email is a side feature of your hosting and you value the 24/7 サポート. If sending is the actual job, do not use bundled host mail at all; SMTP2GO handles deliverability for you, and ZeptoMail does the volume for a fraction of the renewal.

今 -76%

2. A2 Hosting

4.6

Number of Reviews 3.4k +

Avg. Review Rating 4.5 ポジティブ

Customer Support ポジティブ

Starts from $1.95 / mo.

Server Locations

plans

View this deal

Read full review

ホスティング.com (以前の A2 ホスティング) – Best for speed-first sites that send lightly

エントリ: 2.99ドル/月. リニューアル: 10.99ドル/月 (起動). No bulk sending allowed.

A2 Hosting が 4 月に Hosting.com にブランド変更されました 2025, and the rename muddied which email policy applies. What is clear: bulk and marketing email are off the table. The host explicitly tells you to use a third-party service for campaigns, and accounts that cross roughly 1,000 emails a day risk suspension. Published hourly limits conflict by source, landing somewhere between 100 と 500 emails an hour, enforced per email account rather than per domain, so more mailboxes raises your effective ceiling.

Put numbers on it: Hosting.com suspends above about 1,000 emails a day, where InMotion tolerates roughly 6,000 a day before its 250/hour cap bites. The renewal is gentler than most of this group, けれど. Startup re-ups at USD 10.99 a month against SiteGround's USD 17.99, and the speed stack (LiteSpeed, NVMe) 本物です. None of that changes the verdict for sending: this is a fast web host that happens to relay light mail, not a sending platform.

• Per-account limits, so extra mailboxes add headroom
• Gentler renewal: 10.99ドル/月 起動時
• Nine data center regions across four continents
• SPF and DKIM via cPanel deliverability tools

• Bulk and marketing sending banned outright
• Suspension risk above 1,000 emails/day
• Conflicting published hourly caps post-rebrand

こんな方に最適: a performance-focused site that sends transactional mail in the low hundreds per day. 次の場合はスキップします: you need predictable bulk capacity, where Mailgun or SMTP2GO won't suspend you for hitting volume.

評決: Pick Hosting.com if page speed is your priority and email is incidental. Anyone whose product depends on email reaching the inbox should pair it with a relay; Brevo's free 9,000 a month covers more than this host's daily cap without the suspension risk.

3. GreenGeeks Web Hosting

4.6

Number of Reviews 753

Avg. Review Rating 4.2 ポジティブ

Customer Support ポジティブ

Starts from $2.49 / mo.

Server Locations

plans

View this deal

Read full review

GreenGeeks – Best "名前付き" SMTP product among shared hosts

エントリ: 2.95ドル/月. リニューアル: 13.95ドル/月 (Lite). Outbound cap: ~100 emails/hour.

Here is the twist: GreenGeeks is the only host in this group that markets a product literally called "SMTPホスティング," complete with one-click setup, a choice of US or EU sending server, and built-in SPF, DKIM, and DomainKeys. It sounds like a relay. It is still shared-hosting mail underneath, throttled to about 100 emails an hour with a 50 MB message size cap and open-relay detection that blocks anything resembling a campaign.

That 100/hour rate is a quarter of SiteGround's 400/hour floor and 40% of InMotion's 250/hour, so the branding oversells the throughput. What the product does get right is authentication: SPF, DKIM, and DomainKeys configured for you, plus a sending server near your contacts, which helps a small site's mail actually arrive. Renewal on the Lite plan sits at USD 13.95 月, between Hosting.com's USD 10.99 and SiteGround's USD 17.99. For deliverability at volume, a dedicated relay still wins; for a green-minded small site that wants clean authentication out of the box, this is a tidy option.

• Named SMTP product with one-click setup
• SPF, DKIM, and DomainKeys preconfigured
• US or EU sending server, user-selectable
• 30-当日返金窓口

• Effective cap around 100 メール/時間
• Open-relay detection blocks bulk campaigns
• "SMTPホスティング" name implies more throughput than it delivers

こんな方に最適: a low-volume site that wants authentication handled without touching DNS records. 次の場合はスキップします: you read "SMTPホスティング" and expected relay-grade volume, where SMTP2GO or Mailjet is the real thing.

評決: Choose GreenGeeks if you want bundled mail with deliverability basics done for you on a small site. If the word "SMTP" in the plan name is why you're here, buy an actual relay instead; Mailjet's free 6,000 a month sends more than this plan allows in a day.

-75%

4. InMotion Hosting

4.1

Number of Reviews 2.8k +

Avg. Review Rating 4.0 ポジティブ

Customer Support 中性

Starts from $0.99 / mo.

Server Locations

plans

View this deal

Read full review

InMotion Hosting – Best refund safety net

エントリ: 4.99ドル/月. リニューアル: 13.99ドル/月 (発売). Outbound cap: 250 メール/時間.

Picture a small membership site sending welcome emails, renewal notices, and the odd announcement. That is InMotion's email comfort zone: 250 emails an hour, 約 6,000 a day, with a 50-recipient limit per message on shared servers. もっと必要? You file an exception request through their AMP panel, or move to a VPS plan where the shared cap disappears. Outbound runs through MailChannels filtering, which keeps the shared IPs cleaner than a typical cPanel host.

The standout number isn't about sending, it's the refund. InMotion's 90-day money-back guarantee triples the 30 days you get from SiteGround and GreenGeeks, so you can test deliverability for your own audience risk-free. On capacity, its 250/hour sits below SiteGround's 400 but above GreenGeeks' 100. Launch renews at USD 13.99 月, a gentle 2.8x on the USD 4.99 イントロ, and an Amsterdam data center gives EU senders a GDPR-friendly home.

• 90-日帰り, longest in this group
• MailChannels outbound filtering on shared plans
• EU data center option (アムステルダム)
• VPS upgrade removes the hourly cap

• Shared cap of 250 メール/時間
• Bulk sending needs a manual exception request
• No independent inbox-placement track record

こんな方に最適: a cautious buyer who wants three months to confirm mail reaches their audience before committing. 次の場合はスキップします: you already know you need bulk capacity today, where SES or Mailgun starts sending in minutes.

評決: Pick InMotion when the long refund and a managed cPanel experience matter more than raw sending volume. 成長し続ける 6,000 emails a day and the answer isn't an exception ticket, it's a relay; Amazon SES costs USD 10 次のために 100,000 and never throttles by the hour.

5. Amazon Web Services (AWS)

1.9

Number of Reviews 200

Avg. Review Rating 2.1 中性

Customer Support ネガティブ

Starts from $5.83 / mo.

Server Locations

plans

Read full review

Amazon SES – Best price at high volume

無料: 3,000 emails/month for 12 月. それで 米ドル 0.10 あたり 1,000. 設定: テクニカル.

米ドル 0.10 あたり 1,000 メール. Nothing else here comes close on raw price, which is why SES anchors the budget end of any serious sending stack. A million emails a month costs about USD 100, and new AWS accounts get 3,000 free a month for their first year plus up to USD 200 in starter credits. The trade is that SES hands you an engine, not a dashboard: domain verification, sandbox removal, IAM権限, and IP warmup are all on you.

The price gap is the headline. SES bills USD 10 為に 100,000 emails where SMTP2GO charges USD 75 and Postmark lands near USD 126 for the same volume. You pay for that with deliverability legwork. InboxEagle's 2026 test graded SES at roughly 19% primary-inbox placement with a Grade B, because raw IP reputation is the sender's responsibility, not Amazon's. SES added inbox-placement metrics and blocklist monitoring in May 2026, which helps, but you still drive. If you already live in AWS, 私たちの クラウドホスティングの比較 shows where SES fits a wider stack.

• Cheapest at scale: 米ドル 0.10 あたり 1,000
• SMTP relay plus HTTPS API and deep event hooks
• Dedicated IP from USD 24.95/mo (標準)
• 新しい 2026 inbox-placement and blocklist monitoring

• You manage IP warmup and reputation yourself
• Weak out-of-box placement: ~19% primary inbox (InboxEagle)
• AWS console, sandbox limits, and IAM learning curve

こんな方に最適: a developer or ops team sending high volume that can warm an IP and wants the lowest per-email cost. 次の場合はスキップします: you want delivery handled for you, where SMTP2GO trades price for a managed 95.5% inbox rate.

評決: Choose Amazon SES when volume is high, budget is tight, and someone on the team owns deliverability. If nobody wants to babysit IP reputation, 保険料を支払う: SMTP2GO or Postmark will land more mail with none of the warmup work.

SMTP2GO – Best overall for managed deliverability

無料: 1,000 emails/month. 100k/month: 米ドル 75 with dedicated IP. Inbox placement: 95.5%.

SMTP2GO's pitch is the thing most teams actually want: point your app at it and stop thinking about deliverability. EmailTooltester's four-round 2026 test measured 95.5% average inbox placement, the second-highest result in their field, and named it the best free SMTP server three years running. Setup is point-and-send, with DKIM and SPF applied automatically and bounce handling, retries, and suppression managed behind the scenes.

Where SES makes you the deliverability engineer, SMTP2GO is the opposite trade. Its Professional plan runs USD 75 1か月間 100,000 emails with a dedicated IP included, against SES's USD 10 for the same volume where you supply the reputation. It also undercuts Postmark's roughly USD 126 at 100k while landing a near-identical inbox score. The free tier (1,000 月, 200 a day) is tighter than Brevo's 9,000, and reporting retention is only five days on free, but the paid experience is the smoothest here. Real-time analytics, sub-accounts, and webhooks round it out.

• Tested 95.5% inbox placement (EmailTooltester 2026)
• Automatic DKIM and SPF, managed bounce handling
• Dedicated IP included from the Professional tier
• Sub-accounts, webhooks, and live analytics

• Pricier at volume: 米ドル 75 per 100k vs SES's USD 10
• Free tier capped at 200/day
• Five-day report retention on the free plan

こんな方に最適: a business that wants transactional and light bulk mail to just arrive, without managing IPs. 次の場合はスキップします: you have an engineer who'll warm an IP for SES and pocket the savings at scale.

評決: Pick SMTP2GO when deliverability matters more than the per-email rate and you'd rather not touch IP reputation. If you're sending millions and have the talent to manage a sender domain, SES does the same job for a tenth of the cost; if you only need a few hundred transactional mails, ZeptoMail is cheaper still.

Brevo – Best all-in-one (marketing plus transactional)

無料: 300/日 (9,000/月). 100k/month: 米ドル 69. Inbox placement: ~94%.

Say you run both order receipts and a monthly newsletter and you'd rather not stitch two tools together. Brevo (formerly Sendinblue) puts SMTP relay, API, drag-and-drop campaigns, オートメーション, and a light CRM under one login, with transactional and marketing drawing from the same send allowance. Its free tier gives 300 emails a day forever, which is more generous than every dedicated relay here except by raw monthly count.

On price and delivery it holds up against the pure relays. Brevo's USD 69 為に 100,000 emails undercuts SMTP2GO's USD 75 and SendGrid Pro's USD 89.95, and its EmailTooltester 2026 placement of about 94% topped that round's range. 無料, it sends 9,000 a month against SendGrid's zero. トレードオフ: that 300/day free cap throttles bursts, a dedicated IP is a roughly USD 21/mo add-on rather than included, and per-volume pricing gets less sharp than ZeptoMail or SES once you climb past six figures.

• マーケティング, オートメーション, and SMTP in one tool
• Forever-free 300 emails/day
• Strong tested placement: ~94% (EmailTooltester 2026)
• 米ドル 69 per 100k undercuts SMTP2GO and SendGrid

• Free plan throttles at 300/day
• Dedicated IP is a paid add-on (~USD 21/mo)
• Less competitive cost above ~500k/month

こんな方に最適: a small business that wants campaigns and transactional email from a single dashboard. 次の場合はスキップします: you only send transactional mail and want the lowest rate, where ZeptoMail is far cheaper.

評決: Choose Brevo when one tool for marketing and transactional beats best-in-class at either. If you never run campaigns, you're overpaying for features you won't open; Postmark delivers transactional better, and ZeptoMail does it for a fifth of the price.

Twilio SendGrid – Best developer API at scale

無料プランはありません (60-一日トライアル). 50k/month: 米ドル 19.95. 100k: 米ドル 89.95 with dedicated IP.

悪いニュースから始めましょう: SendGrid killed its permanent free plan on May 27, 2025. New accounts now get a 60-day trial at 100 emails a day, then it's pay or leave. What you're buying instead is the most battle-tested email API in the category, Twilio-backed, with deep SDKs, an event webhook system, subuser management, and a separate Marketing Campaigns product when you need it.

For developers the math can still work. Essentials starts at USD 19.95 1か月間 50,000 メール, which beats Mailgun's USD 35 for the same volume. Step up to Pro at USD 89.95 為に 100,000 and a dedicated IP comes included, near-identical to Mailgun Scale's USD 90 and a touch above Brevo's USD 69. 弱点: no current independent inbox-placement score was available for 2026, shared-IP delivery on Essentials can be uneven, and account-deactivation complaints are common enough to plan around.

• Deepest API and SDK ecosystem here
• Essentials 米ドル 19.95 for 50k, under Mailgun
• 米ドルのプロ 89.95 includes a dedicated IP
• Separate marketing-campaigns product

• No permanent free plan since 5月 2025
• Shared-IP placement can be inconsistent on Essentials
• Reports of abrupt account deactivations

こんな方に最適: an engineering team that wants a mature API and integrations at scale. 次の場合はスキップします: you want a free tier to start small, where Brevo and Mailgun still give you one.

評決: Pick SendGrid when API depth and proven scale outweigh the lost free plan. If you're a hobbyist or just testing, start on Brevo or Mailgun's free tier instead; if you want measured deliverability over tooling, Postmark and SMTP2GO publish the scores SendGrid doesn't.

Mailgun – Best deliverability toolkit for developers

無料: 100/日. 50k/month: 米ドル 35. 100k: 米ドル 90 with dedicated IP.

メールガン (owned by Sinch) leans hardest into the engineering side of sending. Beyond the SMTP relay and a strong API, you get inbound email routing and parsing, an email-validation service, send-time optimization, and a deliverability suite (Mailgun Optimize) with inbox-placement testing and guided IP warmup. For a team that treats email as part of the product, that toolkit is the draw.

Pricing sits mid-pack and climbs. Foundation is USD 35 1か月間 50,000 メール, 75% more than SendGrid Essentials at USD 19.95 for the same count. Scale runs USD 90 為に 100,000 with one dedicated IP included, effectively tied with SendGrid Pro's USD 89.95, while extra dedicated IPs cost USD 59 each per month. No standalone independent 2026 inbox score was available, so judge it on tooling and your own setup rather than a published number. Log retention is short on lower tiers, and overages stack up fast above plan.

• Inbound routing and parsing, この層では珍しい
• Email validation and guided IP warmup
• Scale at USD 90/100k includes a dedicated IP
• Deliverability suite built for engineers

• 財団 米ドル 35 for 50k, above SendGrid
• Extra dedicated IPs at USD 59/mo each
• Short log retention and stacking overages

こんな方に最適: developers who want inbound routing, validation, and deliverability tooling in one API. 次の場合はスキップします: you just need cheap outbound volume, where SES or ZeptoMail costs far less per email.

評決: Choose Mailgun when its inbound and validation tooling earns its keep in your product. If you only send outbound transactional mail, you're paying for features you won't call; ZeptoMail handles the sending at a quarter of the cost, and SES wins outright on price at volume.

Postmark – Best transactional inbox placement

無料: 100/月. 50k/month: 〜米ドル 68.50. Inbox placement: 93.8%.

Postmark will reject your marketing blast on purpose, and that is the whole point. By policing what customers send and keeping transactional and broadcast traffic on fully separate Message Streams, it protects the reputation that makes receipts and password resets actually arrive. EmailTooltester's 2026 test put it at 93.8% average inbox placement, with three of four rounds at 95 に 97% (one Microsoft-specific dip pulled the average down). Owned by ActiveCampaign, it pairs clean docs with a fast SMTP and API setup.

You pay for that discipline. で 100,000 emails Postmark lands near USD 126 月, 約 68% more than SMTP2GO's USD 75 and roughly five times ZeptoMail's USD 25. The free tier is a token 100 emails a month, 専用IP (50ドル/月) ニーズ 300,000+ monthly volume to unlock. None of that matters if your transactional mail must hit the inbox, which is the one job Postmark does better than anything else here.

• Top transactional placement: 93.8% (EmailTooltester 2026)
• Separate Message Streams shield transactional reputation
• 45-day detailed activity history
• 速い, well-documented API and SMTP

• プレミアム価格: ~米ドル 126 per 100k
• Token free tier of 100/month
• Dedicated IP gated behind 300k/month

こんな方に最適: a SaaS or store where a failed receipt or reset costs real money. 次の場合はスキップします: you send marketing volume or watch every cent, where Brevo or ZeptoMail fits better.

評決: Pick Postmark when transactional deliverability is non-negotiable and price is secondary. If you also send campaigns, it'll refuse them, so go Brevo; if you want similar placement for less, SMTP2GO lands 95.5% 米ドルで 75 against Postmark's USD 126.

Mailjet – Best EU-based all-in-one on a budget

無料: 6,000/月 (200/日). 不可欠: 17ドル/月 for 15k. EU のデータ常駐性.

Mailjet (also under Sinch) covers similar ground to Brevo, transactional plus marketing in one platform, with a strong pull for European teams: EU data residency baked in for GDPR comfort. Its free tier sends 6,000 月 (上限 200 a day, with Mailjet branding on each message), which is six times SMTP2GO's 1,000-a-month free allowance. Both an SMTP relay and API are included from the free plan up.

Paid pricing is friendly at the entry. Essential is USD 17 1か月間 15,000 emails and removes the branding, and a dedicated IP arrives with the Premium tier from USD 27 月, far below Postmark's USD 50 IP or Mailgun's USD 59. The honest gap is deliverability: no current independent inbox-placement figure was available for Mailjet in 2026, and it historically lands mid-pack, below Postmark and Brevo. Treat it as the value all-in-one, not the delivery champion.

• 豊富な無料枠: 6,000/月
• EU data residency for GDPR
• Dedicated IP from 27ドル/月 (プレミアム)
• Transactional and marketing in one UI

• No verified 2026 inbox-placement score
• Free-plan emails carry Mailjet branding
• Historically mid-pack on deliverability

こんな方に最適: an EU team wanting marketing and transactional in one tool with data kept in Europe. 次の場合はスキップします: inbox placement is your top metric, where Postmark and SMTP2GO post the numbers Mailjet doesn't.

評決: Choose Mailjet for EU data residency and a cheap all-in-one with a roomy free tier. If you'd trade EU hosting for proven delivery, Brevo tested at ~94% for a comparable feature set; if you only send transactional, ZeptoMail is cheaper and more focused.

Zoho ZeptoMail – Best price for transactional-only sending

無料: 10,000-email trial credit. それで 米ドル 2.50 あたり 10,000. Transactional only.

米ドル 2.50 あたり 10,000 メール. Zoho's ZeptoMail prices transactional sending as pay-as-you-go credits with no monthly subscription, and the credits stay valid for six months. There is no marketing module by design: send a campaign and it gets rejected, which keeps the shared IP pools clean and reputation high. For receipts, OTPs, および通知, it's the cheapest credible option in this guide.

The cost gap is dramatic. で 100,000 emails ZeptoMail runs about USD 25, a fifth of Postmark's USD 126 and roughly a third of Brevo's USD 69. A dedicated IP is USD 30 月 (年払い) 選択された地域で, and data centers span the US, EU, インド, とオーストラリア. 2 つの正直な注意点: independent inbox-placement benchmarks for ZeptoMail are scarce, so it lacks the tested scores Postmark and SMTP2GO carry, and Zoho has flagged updated pricing for new sign-ups from July 1, 2026, so confirm the current rate when you register.

• Cheapest credible rate: 米ドル 2.50 あたり 10,000
• Credit-based, no monthly commitment
• Transactional-only keeps reputation clean
• Data centers in US, EU, インド, オーストラリア

• No marketing or broadcast sending allowed
• Scarce independent deliverability data
• New-account pricing changes from 7月 1, 2026

こんな方に最適: a cost-conscious startup or developer sending receipts and OTPs at low cost. 次の場合はスキップします: you need marketing campaigns or a published inbox-placement score, where Brevo or Postmark answers that.

評決: Pick ZeptoMail when you send transactional mail only and price drives the decision. If you need campaigns too, it'll reject them, so use Brevo; if you want a tested inbox rate behind your receipts, SMTP2GO's 95.5% is worth the step up from USD 25 米ドルへ 75 at 100k.