Smtp relay issue from mautic

SSL alert remote xx.xxx.137.31:xxxx, undefined:fatal:unknown CA

server1 SERVER:00000000: SSL_accept error:14094418:SSL routines:ssl3_read_bytes:tlsv1 alert unknown ca

Hi Emma,

would it be possible to get some more background on what is going on?
The amount of information you gave us is scarce, to say the least.

Cheers
JK