==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.9
- Deployed with iRedMail Easy or the downloadable installer? Dl
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): Maria
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I am having issues setting up SMTP in mail clients on Android. Geary on my Ubuntu install works fine and so does IMAP. When I try the same user and pass and server address, port 587 StartTLS and have a LetsEncrypt cert, it says it cant make a connection.

587 is still open (and nmap can see it). I am running a VPN on my phone so not sure if that matters. Ive tried Nine, BlueMail, K-9 Mail and Spark and they all have issues connecting to SMTP. It never opens a connection with the server so no logs on the server.