What tool to use to send millions of e-mails per month

Hi all, I wonder if any of you send millions of e-mails per month and if yes, do you have alternatives for things like SendGrid and Amazon SES? Those services become very expensive when you start sending hundreds of millions per month. I believe those in those categories use different types of tools? Self-hosted software to send e-mail, or something like that?

Use your own IPs. I suggest POSTAL from Atech. Great API, feedback loops.
I’m sure you are sending to double optin lists to people who have especially requested the emails, it won’t be hard to maintain a great domain and IP reputation. You can send even 1 million emails /day on one IP after a proper warmup.

1 Like

Hi @joeyk. Excelent, thanks a lot. That’s exactly what I was looking for, but it never came to me after lots of Google requests. What should I have Googled for?

Yes, my list is very safe and opted in, my open rate is actually close to 40%. But I communicate a lot.

I wonder if there are more options besides POSTAL (not that I need, just for my own knowledge of the market), and how it differs from regular mail sending (SMTP)? I have always wondered what SendGrid or SES do so complex that people won’t be able to install and use it themselves in their own servers.

Sorry for the long letter, but I think you need a quick email university here:

  1. You can send email from your server, using Postfix or other MTA (mail transport protocol) but a simple server starts with a crappy reputation, so you need to improve by warming up your IP.
    Just imagine, that your message is delivered by a really bad smelling door to door salesman. People won’t let you in. -> you land in spam.
    Again: unless you get good reputation, and grow your sending limits gradually.
    You can do it if you have good list, good contacts and you know how to do it.

  2. Some services have wonderful smelling door to door salesman, who are pre-approved (whitelisted). These services maintain a staff, who rigorously kick out bad senders and maintain the infrastructure. Since their livinghood is to keep good senders, Gmail and Outlook, etc welcome their IPs, so they preapprove and whitelist them. Or at least not blacklist them. Such are Sendgrid, Amazon SES, etc. They are called third party SMTP. You don’t install on your server, but you connect them and allow them to send out email in your name using their great IP reputation.

  3. You can send via 2 methods: SMTP and API. The difference is mostly in speed, just like Morse code and Fax. Api is faster, and you want to use it if you send out millions of emails. Bounce feedback is also important: you can have feedback in email, which is the ancient way to do it, or via webhooks. Its more civilized. The third party SMTPs all send webhooks to Mautic, making managing bounces and complaints easy.

  4. Postal is an open source mail server, which makes you a Sendgrid or Amazon SES clone. Meaning: you can tie in email addresses and send emails via your email servers IP from a marketing application (more later). You can make mail server with postfix or PowerMTA as well, but Postal is open source and can provide an email API (Fax not Morse) and supports webhooks (not the ancient bounce emails). So it is superior to those solutions. (According to huge fans like myself).

Okay, but how do I get my millions of email out?

Glad you asked. :slight_smile:
You need to use a Marketing software to manage lists, bounces, interactions, create emails, etc. Like Sendy, Or Mailwizz Or Mautic etc… You install the marketing tool on your server and connect it with a third party SMTP.

So I install Mautic and Postal and I can send millions of emails for free?

No. You need to maintain infrastructure for both. You need the following skills to run a mail server:

  • Feedback loop management
  • DNS management
  • Blacklist management
  • IP reputation monitoring

Moreover you need to

  • clean your lists
  • manage your lists for campaigns
  • implement sunset policy, list splitting, opener management, etc.

Good Luck to you!


Thanks @joeyk. That’s more or less the picture I had in my head, the missing part was just the Postal part (or MTA so to speak) to understand what was under the hood of such services like SendGrid and SES. Of course, as you said, it’s a Postal (there is also MailerQ and others) and lots of administration and side tools.

I was just trying to fill the gap between a small service and millions and millions of users - what were they using? There are a lot of marketing services (like MailerLite) who offer unlimited e-mails so obviously I was trying to understand what’s behind them. I was also trying to be prepared ahead in case my e-mail sending volume gets too big.

In the end I believe the best case for me seems to be ElasticMail. They are as cheap as SES, seems easier to configure and they have “unlimited e-mails” option where they charge per contact. Very handy and flexible, and I don’t have to be stuck in a specific marketing tool.

I have now to check if Mautic has a good integration with ElasticMail. I’m also evaluating MailWizz, still trying to figure out the differences between it and Mautic.

Couple of things I learned by sending a lot of emails:

There are 3 types of senders: good, bad and small.

  • Small senders won’t impact the overall sending score of the IP they are on, so they pay their $30-50 / month and everyone is happy. They could also run a Mautic instance (or other self hosted app) + SES and save $20 / month, but they don’t care. not worth the fuss.

  • Bad senders are sending enough emails to impact the IP reputation in a negative way. You don’t have to send spam to be a bad sender, just send large amount of mail. The providers see every single email you send, and they get reports about them from Gmail. Once you are landing in Spam, they’ll know, so check what you send and if it’s affiliate/workfromhome/makemoney, etc, than you are donzo. Bad senders just make trouble for SMTP’s and they are kicked out really fast.

  • Good senders send a mixture of personalized emails and transactional emails in reliable steady volumes. Only double opt-in lists. They are super-welcome everywhere, but also rare at the same time.

The SMTP providers have to balance the good and the evil get enough small ones to run their business.

There is no such thing as unlimited emails. Before you could raise to unlimited hights, they will judge you if you are good enough for them.


One more comment: unlimited email, but not unlimited number of contacts in your lists.

Does Proxmox Mail Gateway fit into this too and has anyone used it before with Mautic?

Indeed, but very handy in some situations where the number of contacts is not that high but communication is constant.

Quite an interesting discussion. When you are talking about warming up the IP, you are talking about how many emails per day? I wonder whether it is worthwhile to start with it once you are small, so that your IP has a good reputation when you grow. But I guess it is also involving some hassle to monitor the IP reputation, figure out blacklisting problems and anything else. Maybe it makes it easier to get a dedicated IP on Amazon SES and just pay their fees in order to have a reliable service.

Just to chime in here, ++ Postal. It is an Awesome solution!

1 Like

Thank you for the great description. Even if I visited this thread one year later.

Have you used Postal together with Mautic?

When I was researching for Mautic and Postal, I found that some people used to have issues with bouncing notifications.

Thank you again, great post!

Hi, thank you for the kind words.
Looking at the upcoming PRs, I can see, that Mautic 5 will support Postal out of the box, including the feedback loops.

1 Like

Wouldn’t know.if anyone tried this out before and what makes it different to Postal?