Compare Email Services for SaaS

Tools at a glance

Tool	Best for	Starting price (plan, billing)	Key limitation
Postmark	Transactional email from your app	Basic $15/mo, plan starts at 10,000 emails a month (monthly billing)	Free plan is capped at 100 emails a month
Resend	Developer API with a free starting tier	Free: 3,000 emails a month. Pro $20/mo for 50,000 emails	Free plan is limited to 100 emails a day
SendGrid	High-volume API sending plus marketing campaigns	Essentials $19.95/mo for the 50,000 to 100,000 email band	The email API free trial lasts 60 days; ongoing free use is limited to Marketing Campaigns
Mailgun	Email API and SMTP relay for engineering teams	Basic $15/mo for 10,000 emails a month	Email and validation overages are billed on usage
Customer.io	Behavior-triggered lifecycle email	Essentials $100/mo, billed monthly; 10,000 profiles $145/mo	Cost rises with profile count; Premium needs a custom profile volume
Loops	Product and lifecycle email for small teams	Growing Audience $99/mo for unlimited sends to subscribers	Free plan adds a Loops footer and a 10 emails per second limit
Encharge	SaaS behavioral email with verification included	Growth $99/mo monthly or $79/mo billed annually, up to 2,000 subscribers	No free plan; listed tiers cap at 2,000 subscribers
Drip	People-based automation with unlimited sends	$39/mo for 1 to 2,500 people	14-day free trial only; no ongoing free plan
Klaviyo	Profile-based email, especially for online stores	Email plan from $20/mo at 500 profiles	Email plus SMS prices are on request
Userlist	B2B messaging for SaaS users and companies	Basic $149/mo at up to 10,000 users	Enterprise plan is custom and priced on request
Brevo	Low-cost newsletters and transactional mail	Free: 300 daily sends. Starter $9/mo from 5,000 emails a month	Free plan has a daily sending cap
Mailchimp	Newsletters for smaller contact lists	Free up to 250 contacts; Standard $20/mo at 500 contacts	Price moves up with each contact tier
ActiveCampaign	Marketing automation combined with a CRM	Starter $15/mo at 1,000 contacts	No free plan; a free trial is offered
ZeroBounce, NeverBounce, Kickbox	Verifying addresses before import or send	Pricing on request	They verify addresses; they do not send email

What transactional senders cost at real volumes

Transactional pricing depends on how many emails you send in a month. The table lists the plan that applies at each volume. Where a volume falls outside a listed band, the cell says so.

Sender	10,000 emails a month	50,000 emails a month	100,000 emails a month
Postmark	Basic $15/mo	Basic $55/mo	No tier listed at this size (125,000 emails: Basic $115/mo)
Mailgun	Basic $15/mo	Foundation $35/mo after the first month	Scale $90/mo after the first month
Resend	No tier listed at this size (free plan covers 3,000 a month)	Pro $20/mo	Scale $90/mo
SendGrid	No tier listed at this size	Essentials $19.95/mo	Essentials $19.95/mo or Pro $89.95/mo, depending on the plan selector band

Postmark's Basic price at 50,000 emails ($55) is more than Resend Pro at the same volume ($20). Postmark's per-email model is worth it when you value the separation of transactional traffic and its support; on price alone, compare the bands at your actual volume.

What contact-based platforms cost at real list sizes

Marketing platforms price by contacts, profiles or subscribers. Compare at the size you will reach within the next year, not at today's count, because most tiers step up with growth.

Platform	About 2,500 contacts	About 10,000 contacts	About 25,000 contacts
Drip	$39/mo (1 to 2,500 people, unlimited sends)	$154/mo (9,001 to 10,000 people)	$369/mo (22,501 to 25,000 people)
Klaviyo (email plan)	$60/mo (2,500 profiles)	$150/mo (10,000 profiles)	$400/mo (25,000 profiles)
Customer.io (Essentials, billed monthly)	No tier listed at this size	$145/mo (10,000 profiles)	$235/mo at 20,000 profiles or $325/mo at 30,000 profiles; no 25,000 tier listed
Encharge (Growth)	$99/mo monthly or $79/mo annually, up to 2,000 subscribers only	No tier listed at this size	No tier listed at this size
Loops (Growing Audience)	$99/mo for unlimited sends to subscribers	$99/mo, same price	$99/mo, same price

Customer.io's Startup Program is the exception to these numbers. Its pricing page says eligible early-stage companies that have raised under $10M can receive 12 months free. Check the eligibility terms on the vendor's pricing page before you plan around them.

Tool-by-tool notes

Postmark

Postmark suits SaaS products that need receipts, password resets and billing notices delivered quickly. Basic is $15 per month and starts at 10,000 emails. Pro is $16.50 per month and Platform is $18 per month at the same starting volume. The free plan covers 100 emails a month with no overages. Its focus is transactional mail, so if your main need is large newsletter sends, compare it against a marketing platform before you commit. Pricing: postmarkapp.com/pricing.

Resend

Resend is a good fit for engineering teams that want an API and a free starting tier. The free plan includes 3,000 emails a month, 100 emails a day and 3 domains. Pro is $20 per month for 50,000 emails and Scale is $90 per month for 100,000. Its marketing offer lists 1,000 free contacts, and Pro marketing is $40 per month at 5,000 contacts. The daily cap on the free plan is the limit most teams notice first. Pricing: resend.com/pricing.

SendGrid

SendGrid covers high-volume API sending and marketing campaigns from one account. Essentials is $19.95 per month for the 50,000 to 100,000 email band, and Pro is $89.95 per month for 100,000 to 2.5 million emails. Marketing Campaigns has a free plan for up to 2,000 contacts and 6,000 emails a month. The API free trial is time-limited to 60 days at 100 emails a day, so plan for a paid tier before the trial ends. Pricing: twilio.com/en-us/products/email-api/pricing.

Mailgun

Mailgun offers an email API and SMTP relay, which many engineering teams prefer for custom sending. Its free plan allows 100 emails a day. Basic is $15 per month for 10,000 emails, Foundation is $35 per month for 50,000 and Scale is $90 per month for 100,000. Foundation and Scale include one free month. Its pricing model also includes usage-based overages for email and validation, so verification volume adds to the bill. Pricing: mailgun.com/pricing.

Customer.io

Customer.io is built for behavior-triggered lifecycle email: onboarding series, feature nudges and win-back flows that start from product events. Essentials is $100 per month, billed monthly, and includes a visual workflow builder. Profile-based tiers run from $145 per month at 10,000 profiles to $325 per month at 30,000. Premium has custom profile volume and pricing. Costs grow with profile count, so model your growth before you choose it. Pricing: customer.io/pricing.

Loops

Loops is a simple option for small SaaS teams that want product and lifecycle email in one place. The free Early Stage plan includes up to 4,000 sends in any rolling 30 days to your 1,000 newest contacts, with a Loops footer and a limit of 10 emails per second. The Growing Audience plan is $99 per month for unlimited sends to subscribers and includes transactional sends to users outside your audience. Pricing: loops.so/pricing.

Encharge

Encharge targets SaaS behavioral email. Growth is $99 per month billed monthly or $79 per month billed annually, for up to 2,000 subscribers. Premium is $159 per month, or $129 per month billed annually, and adds HubSpot and Salesforce connections and transactional email. The pricing page says email verification is included on paid plans, which is useful if you need it without a separate tool. There is no free plan, and both listed tiers cap at 2,000 subscribers. Pricing: encharge.io/pricing.

Drip

Drip bills by people in your account and includes unlimited email sends, dynamic segments and up to 50 workflows on its lower tiers. The 1 to 2,500 people band is $39 per month, and the 9,001 to 10,000 band is $154 per month. Drip has a 14-day free trial with no credit card required and no ongoing free plan. Pricing: drip.com/pricing.

Klaviyo

Klaviyo is strongest when your email is tied to a product catalog or an online store. Its free plan covers 250 active profiles and 500 email sends a month. The email plan starts at $20 per month for 500 profiles, rising to $150 per month at 10,000 profiles and $400 per month at 25,000. Email plus SMS prices are on request. Pricing: klaviyo.com/pricing.

Userlist

Userlist focuses on messaging for SaaS users and the companies they belong to, so it fits B2B products that segment by account. Basic is $149 per month at up to 10,000 users and Professional is $349 per month at the same size. Professional adds A/B split testing and conversion goals. Enterprise has custom message limits and is priced on request. Pricing: userlist.com/pricing.

Brevo

Brevo is a low-cost option for newsletters and some transactional mail. Its free plan includes 300 daily sends and storage for up to 100,000 contacts. Starter is $9 per month for at least 5,000 emails a month with no daily limit, and Standard is $18 per month at the same volume, adding automation, A/B testing and advanced reports. The free plan's daily cap means it fits low-frequency sending best. Pricing: brevo.com/pricing.

Mailchimp

Mailchimp suits newsletters for smaller contact lists. Its free plan includes up to 250 contacts and 500 sends a month. Standard starts at $20 per month for 500 contacts, and the price moves up at each contact tier, reaching $100 per month for 2,501 to 5,000 contacts. It is a reasonable choice for campaigns, but the price climbs faster than the sending-based tools as the list grows. Pricing: mailchimp.com/pricing.

ActiveCampaign

ActiveCampaign combines email automation with a CRM. Starter is $15 per month at 1,000 contacts, Plus is $49, Pro is $79 and Enterprise is $145, each at the 1,000-contact starting point. Prices rise with contact count. It offers a free trial but no ongoing free plan, and it fits teams that want sales and marketing in one system. Pricing: activecampaign.com/pricing.

List verification: ZeroBounce, NeverBounce and Kickbox

ZeroBounce, NeverBounce and Kickbox check email addresses before you send to them. They do not deliver mail, so you still need a sender. Pricing for each is on request, so check the vendor's pricing page for current terms. If you pay for verification per check, budget for re-verifying a list when it grows, not only once at import.

Two of the tools above include verification in their pricing. Encharge's pricing page says email verification is included on plans, and Mailgun bills validation as part of its usage-based overages. Count that cost before you choose a sender, because verification done through the sender is billed on the sender's usage.

Which to start with

If you need	Start with	Because
Receipts, login codes and billing notices sent from your app	Postmark	Priced per email from 10,000 a month; Basic is $15 per month
An email API with a free starting tier	Resend or Mailgun	Resend's free plan covers 3,000 emails a month; Mailgun's allows 100 a day
Lifecycle emails triggered by product events	Customer.io or Loops	Customer.io Essentials is $100 per month; Loops Growing is $99 per month for unlimited sends to subscribers
A SaaS list under 2,000 subscribers with verification included	Encharge Growth	$99 per month monthly or $79 per month annually, and the pricing page says verification is included
A low-cost newsletter and some transactional mail	Brevo	Free plan for low volume; Starter is $9 per month from 5,000 emails a month
A clean list before the first import	ZeroBounce, NeverBounce or Kickbox	Verification tools check addresses before sending; pricing is on request

How to choose

Start with the mail that cannot fail. For most SaaS products that is billing and account mail, which should go through a sender built for transactional traffic. Then choose a marketing platform for campaigns and lifecycle sequences, and keep the two separate so a marketing mistake cannot slow down receipts.

Next, compare at your next year's volume. A tool that is cheap at 2,000 contacts can be expensive at 25,000, and a free plan that works for testing may have a daily cap that blocks a launch. Use the cost tables above and check each vendor's pricing page for the band that applies to you.

Finally, decide who will run it. An API-first sender needs an engineer to maintain templates and webhooks. A marketing platform needs someone to build workflows weekly. Pick the tool your team can operate every week.

Setup and migration checklist

1. Verify your domain. Set up SPF, DKIM and DMARC for the sending domain before the first send, and confirm the records resolve.
2. Separate the streams. Send transactional and marketing mail from different subdomains or accounts, so a campaign problem does not affect receipts.
3. Verify the list. Run your existing contacts through a verification tool and remove invalid addresses before importing them.
4. Move suppression lists. Import unsubscribes and bounces from your old tool first, so you do not email people who already opted out.
5. Warm up gradually. Start with your most engaged contacts and increase volume over several weeks.
6. Test both failure paths. Send a message to an invalid address and an unsubscribe request, then confirm both appear correctly in the new tool.
7. Check the plan band. Confirm your monthly volume and contact count sit inside the plan you chose, and set an alert before you reach the next band.

Billing platforms such as Stripe, Paddle and Lemon Squeezy handle payments rather than email. Their pricing pages describe per-transaction fees with no monthly platform fee on standard plans. Connect them to your sender, so payment events trigger the right messages.

How this page is prepared

Each price on this page comes from the vendor's pricing page, checked on 7 October 2026. Where a vendor does not list a price for a size or plan, the table says so rather than estimating. We read each vendor's public pricing and documentation to write the summaries. Prices change, so confirm the current terms on the vendor's site before you buy. To report a correction, use the contact page and name the tool and the page.

Frequently asked questions

Which email service should a SaaS product start with?

Start with a transactional sender for receipts, login codes and billing notices. Postmark's Basic plan is $15 per month and starts at 10,000 emails. Add a marketing platform when you need campaigns or lifecycle sequences.

Do I need both a transactional sender and a marketing platform?

Many SaaS teams do. Transactional mail has to arrive reliably, and marketing mail depends on consent and engagement. Keeping them separate protects receipts if a campaign goes wrong. Some platforms, such as Resend, Mailgun and SendGrid, offer both on one account, so check whether a single account meets your needs before you split them.

What do ZeroBounce, NeverBounce and Kickbox cost?

Pricing for each is on request. Check the vendor's pricing page for current terms. These tools verify addresses; they do not send email, so you still need a sender.

Are the free plans enough to test a setup?

They can be, if your test volume stays under the limits. Resend's free plan covers 3,000 emails a month with a 100-a-day cap, Mailgun's allows 100 emails a day, and Postmark's covers 100 emails a month. Check the daily and monthly caps before you run a launch on a free plan.

How do I move to a new sender without losing deliverability?

Verify your domain records, import your suppression list first, and warm up the new sending setup gradually, starting with your most engaged contacts. Send a test to an invalid address and an unsubscribe request to confirm both work before you switch the full list.

Which plan should I check first on the pricing pages?

Find the band that matches your volume for the next year, not today. Sending-based plans and contact-based plans step up at different points, so the cheapest tool at your current size may not be the cheapest at your planned size.

What if neither tool in a comparison fits?

Use the alternatives hub to see which substitutes are worth a trial. If your need is raw SMTP throughput or dedicated sending infrastructure, the high-volume page is the closest starting point on this site.