SendGrid vs Postmark

Reachkit makes a cold email tool, not an app email service, so it isn’t a contender on this page. I checked every price below in October 2026 on each vendor’s own pages.

SendGrid and Postmark do the same job: they deliver the email your software triggers, through an API or SMTP, to people who asked for it. My verdict comes down to volume and to how much you want to configure. SendGrid is cheaper across the middle of the range and gets you a dedicated IP sooner. Postmark is built around transactional mail, separates it from bulk mail by default, and keeps longer logs on every plan.

Pick SendGrid if:

• You send 50,000 to 300,000 emails a month and price matters most: $19.95 for 50,000 against Postmark’s $55.
• You want your own IP address below 300,000 emails a month. Pro includes one from $89.95.
• You also want contact lists, signup forms and a newsletter editor from the same vendor, in Marketing Campaigns (billed separately).

Pick Postmark if:

• You send around 10,000 emails a month and want a paid plan from $15.
• Password resets and receipts matter more than newsletters, and you’d like them kept off the IP ranges your bulk mail uses by default.
• You trace delivery problems in the logs and want 45 days of message history without paying extra.

Checked October 2026. Prices in USD, billed monthly, from each vendor’s own pages.

SendGrid and Postmark both let you start without a card, and Postmark adds a hand review of every new account before mail can leave your own domains.

SendGrid: new accounts get a 60-day trial at 100 emails a day, then move to a paid plan. You authenticate your domain with SPF and DKIM, add link branding, and on Pro set up reverse DNS. Your code calls the v3 Mail Send API or points at the SMTP relay, with official client libraries. Since February 2026 sendgrid.com lives on twilio.com, which Twilio called a website change with no API or price change.

Postmark: a free Developer plan covers 100 emails a month for testing, with no end date. After adding DKIM and Return-Path records for your domain, you wait for approval: until a person approves the account, mail can only go to domains you’ve verified, and link tracking stays off. Postmark’s help center puts the review at under 24 hours on weekdays, though Trustpilot reviewers in 2025 reported waits of up to a week, and one a refusal without an explanation. Official libraries include Ruby, Python, PHP, Node.js, .NET and Java, and one API call can carry up to 500 messages.

On SendGrid the friction tends to come later: Capterra’s review summary flags unpredictable account restrictions (see what users say below). If a launch date depends on email, I’d open the Postmark account a few days early.

Postmark separates app email from bulk email by default and keeps most senders on shared IP pools, while SendGrid puts a dedicated IP within reach at a lower volume and leaves the traffic split to you.

Postmark runs transactional mail and broadcasts, such as newsletters, on separate message streams. In Postmark’s words, “Transactional and broadcast (bulk) traffic does not mix in Postmark, including IP ranges.” Everyone sends from shared pools unless they buy a dedicated IP, which Postmark sells for $50 a month to Pro and Platform customers sending at least 300,000 a month. Postmark even argues that “for most people, a pristine shared IP pool will have the best results”. A new dedicated IP is warmed by Postmark (its recommendation) or by you; with Postmark’s managed warmup, most reach full volume in 3 to 6 weeks, per Postmark.

SendGrid puts trial and Essentials accounts on groups of shared IPs. Pro includes one dedicated IP with automated warmup, IP pooling and reverse DNS, and adds bounce and block classifications to the reports. Extra IPs cost $30 a month each, one a month through the console, and Twilio advises at least two once you send 200,000 to 300,000 a month. Keeping receipts and newsletters apart is possible on Pro, but it’s your configuration, not the default.

Both police list quality. Postmark’s terms set limits: spam complaints under 0.1% and bounces under 10%. Twilio’s Email Policy sets no numbers, and its acceptable use policy lets it suspend accounts that break the rules.

Postmark keeps far more history by default, and SendGrid Pro bundles extras such as address validation, subusers and SSO.

• Message history. SendGrid keeps 3 days of searchable activity on Essentials and 7 on Pro, and sells more history at a price it doesn’t publish. Postmark keeps 45 days on every plan, adjustable from 7 to 365 days from $5 a month on Pro and up, and keeps statistics indefinitely.
• Bounces and events. Postmark suppresses hard bounces and spam complaints automatically and sends webhooks for deliveries, bounces, opens and clicks. SendGrid allows 2 event webhooks on Essentials and 5 on Pro.
• Inbound mail. SendGrid’s Inbound Parse webhook posts incoming mail to your app. Postmark does the same on Pro and Platform, not Basic. Neither gives you an inbox to read and answer replies in.
• Teams. SendGrid Essentials has 1 teammate; Pro allows up to 1,000, plus subusers and SSO. Postmark allows 4 users and 5 domains on Basic, 6 and 10 on Pro, and no cap on Platform.
• Address checks. SendGrid Pro includes 2,500 address validations. Postmark’s own comparison page lists address validation as a SendGrid-only feature.
• Support. SendGrid’s help center gives every plan tickets, paid plans live chat, and Pro and up phone callbacks. Postmark’s comparison page says “Our average time to first response is under two hours.”

Neither SendGrid nor Postmark writes your emails with AI; the difference is in what developers and AI assistants can do through each one.

Twilio wrote in March 2026 that “SendGrid doesn’t offer native AI tools”. Postmark has no AI writing features either.

For AI assistants, the gap is real. MCP is an open standard that lets assistants such as Claude and ChatGPT work inside other apps. Postmark publishes an official, open-source MCP server that runs on your own machine. Version 2.0 (July 2026) has 24 tools, labelled read-only or destructive, and it can send email, so its README warns: “Never configure auto-approval for sending or destructive tools in untrusted environments.” Postmark also published open-source Agent Skills for coding assistants such as Claude Code and Cursor in February 2026. Twilio’s official MCP server, in public beta, searches SendGrid’s docs and support articles but is read-only and makes no API calls. Community-built SendGrid MCP servers exist.

On the API side, SendGrid adds API key permissions and subusers. Postmark gives each server its own API key, added IP allowlisting for API sends in August 2026, and since March 2026 has a Bulk API for one message to many recipients, which support has to switch on.

Postmark sells one product in three plans, while SendGrid is part of a Twilio lineup where the right product depends on what you send and how much.

SendGrid is two subscriptions. The Email API covers mail your code sends. Marketing Campaigns, billed separately, adds contact storage, segments, signup forms, A/B tests, scheduling and, on Advanced, automation. Basic costs $15 a month for 5,000 contacts and 15,000 sends, rising to $200; Advanced runs from $60 to $900. An app that needs both pays both, for example $19.95 plus $15, or $34.95 a month.

Twilio Email is a third route. Generally available since May 2026 and built on SendGrid technology, it charges $0.0013 an email with no monthly fee and no feature tiers. Twilio calls it and SendGrid “two separate tools for different purposes”. Below about 15,000 emails a month it costs less than SendGrid Essentials, and at 10,000 it comes to $13, against $15 on Postmark Basic.

Postmark keeps everything in one account. Newsletters go out on a Broadcast stream next to your transactional stream, under the same plan, rather than in a separate marketing product.

The owners differ too. Twilio bought SendGrid in February 2019 for about $3 billion. ActiveCampaign bought Postmark from Wildbit in May 2022; Postmark has been sending email since 2010.

SendGrid is cheaper from 50,000 to 300,000 emails a month, Postmark is cheaper at 10,000, and from 700,000 the answer depends on whether you need a dedicated IP.

Assumptions: list prices from each vendor’s public pricing page in October 2026, monthly billing, the cheapest plan that fits, no tax. Postmark bills monthly only; its FAQ answers the annual question with “Not right now, but we’d like to!”

Overage changes a few rows. At 300,000 on shared IPs, SendGrid Essentials 100k plus 200,000 extra emails at $0.00088 each comes to $210.95, on the rates in Twilio’s 2025 pricing sheet, against $245 on Postmark Basic. Postmark charges $1.15 to $1.80 per 1,000 extra emails, and Twilio’s pricing page advises that “upgrading to the next tier usually beats paying overages”. Above 1.5 million a month Postmark quotes through sales, while SendGrid lists Pro up to 2.5 million before Premier’s custom pricing.

Both tools rate well on G2 and Capterra and poorly on Trustpilot, where reviews about blocked accounts and support collect. Ratings as of October 2026:

SendGrid’s samples are many times larger, so one review moves its averages far less.

SendGrid: on G2 and Capterra the praise goes to the API, how easily it plugs into other software, and deliverability. The criticism centers on accounts: of 53 Capterra reviews about unpredictable restrictions, the site’s summary rates 79% negative, and Trustpilot’s summary leads with support. On price, one r/SaaS commenter still calls its $19.95 flat rate sensible between 10,000 and 50,000 emails.

Postmark: setup scores sit above 9 out of 10 on G2’s compare pages. On Trustpilot the same three complaints come back in 2025 and 2026 reviews: slow support, approval waits and whole accounts shut down, transactional mail included. Even a two-star review from May 2026 praises the product (“Great system. Great deliverability. Fair pricing.”) while its complaint is about customer service. Several reviewers date a decline to the ActiveCampaign sale.

This is our product, and it only fits one kind of reader here. Reachkit doesn’t send receipts or password resets. If you looked at SendGrid or Postmark to email prospects who never signed up, both providers’ rules forbid it, and that’s the job Reachkit is built for. It sends from Google, Microsoft or other inboxes you connect, with no per-inbox fee, or it registers separate domains at $15 a year, adds Google or Microsoft inboxes at $5 a month each and turns on AI warmup for every one. Plans start at $39 a month. See how it compares with cold email tools in Reachkit vs Instantly and Reachkit vs Smartlead.

Moving between SendGrid and Postmark means taking your domain and your suppression lists with you and rebuilding the rest, since IPs, logs and API keys stay with the old provider.

• Domain: authenticate it again on the new side (DKIM and Return-Path on Postmark, SPF and DKIM on SendGrid).
• Suppressions: export bounces, spam reports and unsubscribes first. Postmark’s SendGrid migration guide maps them to its Bounce and Suppressions APIs, and notes that Postmark has no unsubscribe groups.
• Templates: SendGrid’s transactional templates map to Postmark’s Templates API, which only works when you send through the API, not SMTP.
• SMTP and limits: Postmark doesn’t support port 465, and its guide sets 10 MB and 50 recipients per message.
• Webhooks: SendGrid’s event webhook becomes several Postmark webhooks (delivery, bounce, open, click and more), with different field names.
• Dedicated IP: a new IP starts without reputation. Postmark’s managed warmup takes 3 to 6 weeks; SendGrid Pro warms automatically.

Postmark’s guide was first published in 2017, so check field names against the current API docs. Going to Postmark, get the account approved first. Going to SendGrid, the trial’s 100 emails a day won’t carry production traffic, so plan on a paid plan. Either way, I’d move one stream at a time, receipts first.

I’d choose by volume and by how much setup you want to own. Below 10,000 emails a month, or where a lost password reset costs you a customer, I’d test Postmark first: separate streams by default and 45 days of logs make delivery problems easier to trace. From 50,000 to a few hundred thousand a month, SendGrid’s prices are hard to argue with, and its dedicated IP comes at a lower volume. Whichever you pick, budget for an account review and keep your bounce rate low, because both providers can stop an account that slips.

Related: the SendGrid profile, the Postmark profile, SendGrid alternatives, Mailgun alternatives and the Amazon SES profile.