I have a raspberry pi running postfix. I Realised unless I open port 25 I absolutely cannot receive emails (I have 587 open and can send but not receive them). However I heard there are scaries online which someone could potentially send emails from your server without consent. I believe as well my ISP doesn’t block port 25. Is there anything I should do right now before opening port 25, or should everything be safe enough?
Mango mail, porkbun, proton mail
Each does a slightly different niche.
Mango is cheap, but limits outbound mail. Porkbun has a good all-around mail service, bit is a little more costly. Proton is very secure, but can be inconvenient for export (though it can be done, it requires purchase of a month of business service to export away from them).