How to configure relay correctly?

ivaneliseeff

Hey, everybody!

I have configured mailcow as a single service for now, but a lot of outgoing mail is not being delivered because the ISP ip is in spam databases.

I plan to connect an additional smtp server and immediately a question arose - how to correctly configure this server to work only to send those emails that could not send the main one? Is it necessary to install mailcow on the second server as well, or is it enough to put the usual postfix? Sorry if this question has arisen often, I have just started working with your product.

esackbauer

Seems like you are using a dynamic “end user” IP address, and this is more like a hobby project?
It would be better to simply use a professional relay service like sendgrid.com, they allow 100 mails per day for zero cost.
Just configure the sendgrid address you will get when you register with them as “sender dependent transport map” and use this in your mail domain.

ivaneliseeff

No, the address is not dynamic.
We are placed in digital ocean, they have a lot of addresses in spam databases.

sendgrid will not work either, we send a lot of automatic notifications to our clients.

esackbauer

ivaneliseeff
Then there are 2 possibilites in my view:

Find a hosting service which has a good reputation for hosting mail servers and move mailcow there
Pay for a reliable relay service (sendgrid and others have also paid plans for much more mails per month)

IdrisK

I am using Google Workspace.
Starter account, for 5,5 USD per month for one users this ist enough.

I have setup the domain in google and on mailcow. As mx record I am using my mailcow. Incoming mails are delivered directly to mailcow. Outgoing mails are delivered from mailcow via google smtp relay. mails addressed to configured domains in mailcow never leave mailcow and are delivered internally without smtp relay.

With this setup I can create mailboxes how much I want without more costs on google side.

The external delivery I perfect. Gmail servers have from my point of view a good reputation.

IdrisK

Yes, both solutions are possible. The decision you have to make based on your needs.

I used as howto for configuration of the smtp relay this YT Video:
https://youtu.be/oUZvio31nZY