Best SMTP Services for Bulk Email in 2026: An Honest Comparison

An SMTP service is the “post office” behind your bulk email software. Your sender (for example HAAN MAIL PRO) writes and personalises the messages; the SMTP service delivers them to Gmail, Outlook, Yahoo and every other inbox. Choosing the right one decides how much you pay, how many emails you can send per day and, most importantly, how many land in the inbox.

This comparison covers the SMTP services people use most for bulk email, what each is good at, and how to choose. Prices and plans change often, so check each provider’s pricing page before you sign up.

What makes a good SMTP service for bulk email?

• Deliverability: a good reputation with Gmail, Outlook and Yahoo, and tools to keep it that way.
• Sending limits that match your volume, per day and per month.
• Authentication support: easy SPF, DKIM and DMARC setup for your own domain.
• Bounce and complaint handling, so bad addresses are removed automatically.
• A fair policy for your use case. Some services only allow transactional email (receipts, password resets) and will close accounts that send newsletters or outreach.
• Price per 1,000 emails at the volume you actually send.

Quick comparison

Service	Best for	Pricing model	Setup effort
Amazon SES	High volume at the lowest cost	Pay per email (about $0.10 per 1,000)	High
Brevo	Small businesses and newsletters	Free tier with a daily cap, then monthly plans	Low
Mailgun	Developers and growing senders	Monthly plans by volume	Medium
SendGrid	Established marketing programs	Monthly plans by volume	Medium
Google Workspace	Low-volume outreach from your own domain	Per user per month	Low
Zoho Mail	Low-volume business email	Per user per month	Low

Amazon SES

Best for: sending large volumes as cheaply as possible.

Amazon Simple Email Service is the lowest-cost option at scale, at roughly $0.10 per 1,000 emails. It’s a pure sending service: no templates or contact lists, which is fine when your bulk email software handles those.

• Pros: very low cost, high limits once approved, good deliverability for clean lists.
• Cons: technical setup in the AWS console; new accounts start in a sandbox (you can only send to verified addresses, with a low daily limit) until you request production access and explain how you collect addresses. Amazon reviews bounce and complaint rates closely.
• SMTP host: email-smtp.<region>.amazonaws.com, port 587, with SES SMTP credentials (not your AWS password).

Brevo (formerly Sendinblue)

Best for: small businesses that want a simple start.

Brevo offers SMTP relay alongside its marketing tools, with a free tier that has a small daily sending cap and paid plans priced by monthly volume.

• Pros: quick setup, friendly interface, free tier for testing, allows marketing email.
• Cons: the free tier’s daily cap is low; strict about list quality and opt-in.
• SMTP host: smtp-relay.brevo.com, port 587, with the SMTP key from your account.

Mailgun

Best for: growing senders who want detailed logs and control.

Mailgun is a developer-focused sending service with good analytics, logs and validation tools.

• Pros: reliable delivery, detailed event logs, email validation add-on, EU and US regions.
• Cons: plans are priced for steady volume; the dashboard is more technical.
• SMTP host: smtp.mailgun.org (or the EU host), port 587, with the SMTP login for your sending domain.

SendGrid

Best for: companies with an established marketing program.

Twilio SendGrid is one of the largest email platforms, with SMTP relay, an API and marketing features.

• Pros: proven at very large volumes, dedicated IP options, strong documentation.
• Cons: account approval can be strict for new senders; support depends on your plan.
• SMTP host: smtp.sendgrid.net, port 587, username apikey and an API key as the password.

Google Workspace

Best for: personal outreach from your own domain at low volume.

Google Workspace mailboxes can send about 2,000 messages a day each. They aren’t a bulk email service, but for a few hundred carefully targeted emails a day, mail from a real Workspace mailbox often performs very well, and you can rotate several accounts for more volume.

• Pros: excellent reputation, replies land in a normal inbox, easy setup with an App Password.
• Cons: daily limits per user; not meant for large newsletters; Google suspends accounts that send spam.
• Read our guide: how to send bulk email with Gmail.

Zoho Mail

Best for: small businesses already using Zoho.

Zoho Mail is a business mailbox service with SMTP access. Like Google Workspace, it’s built for normal business email, with per-user sending limits, so treat it as a low-volume option. For transactional email, Zoho offers a separate service (ZeptoMail).

What about Outlook and Microsoft 365?

Microsoft 365 mailboxes can send through smtp.office365.com, but Microsoft has been retiring password-based SMTP sign-in (“basic authentication”) in favour of modern sign-in, and its mailboxes have low recipient limits for bulk use. Check with your administrator whether SMTP AUTH is still allowed for your tenant before relying on it, and prefer a dedicated sending service for bulk email.

How to choose

• Under about 500 emails a day, mostly people you know: Google Workspace or Zoho Mail.
• A few thousand a day, newsletters or outreach: Brevo or Mailgun, or several Workspace accounts with rotation.
• Tens of thousands a day or more: Amazon SES for cost, SendGrid or Mailgun for tooling.
• Transactional email only (receipts, password resets): any of the dedicated services, or providers such as Postmark that specialise in it.

Use more than one: SMTP rotation

You don’t have to pick only one. Bulk email software with SMTP rotation sends each campaign through several accounts in turn, for example two Workspace mailboxes plus Amazon SES. Each account stays under its limit, and if one provider has a problem the others keep sending.

In HAAN MAIL PRO, you add each account to the SMTP Pool, test it and turn it on. Campaigns then rotate through all active accounts automatically, with delays and jitter between emails. The user guide shows how.

Whatever you choose, authenticate your domain

No SMTP service can fix an unauthenticated domain. Set up SPF, DKIM and DMARC for the domain in your From address before your first campaign; every provider above explains the exact records for its service. Our SPF, DKIM and DMARC guide explains what each record does.