Is there any special setting for DeltaChat in firewalls?

Delta Chat version

Expected behavior

Actual behavior

Steps to reproduce the problem

Screen snapshots

Debug logs

If applicable, debug logs can be copied from within the Delta Chat app: 

Open the _Settings_ menu -> _About_ -> _version number|Info_.

Alternatively from the Android system log:

` adb logcat -v time -s DeltaChat `

This log contains private data (e.g. mail address, provider information) which shall be removed or anonymised prior to posting.

Which ports should be opened for deltachat in firewall

the IMAP & SMTP ports of your email provider?