Strange smtp problem

SYSTEM INFORMATION
OS type and version centos 7
Virtualmin version 7.5

why i get the error: Cannot connect to SMTP server 2a02:1388:14b:7ffe:a00:27ff:fe8d:32c3 (2a02:1388:14b:7ffe:a00:27ff:fe8d:32c3:587), connect error 10061. when i am trying to send an email using the thunderbird

thank you

nikos

Check Virtualmin mail log files, it should have a clue why its failing.

Steve

where is the log files?