php - How to solve SMTP connection problem in Perfex CRM

Question

I'm getting the following error Email SMTP setting of Perfex, please help

Connection: opening to smtppro.zoho.com:587, timeout=30, options=array ( )
Connection: opened
SERVER -> CLIENT: 220-server12.thulo.com ESMTP Exim 4.93 #2 Tue, 26 Jan 2021 22:22:49 +0545 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.
CLIENT -> SERVER: EHLO crm.d20labs.art
SERVER -> CLIENT: 250-server12.thulo.com Hello crm.d20labs.art [165.22.215.101] 250-SIZE 52428800 250-8BITMIME 250-PIPELINING 250-AUTH PLAIN LOGIN 250-STARTTLS 250 HELP
CLIENT -> SERVER: STARTTLS
SERVER -> CLIENT: 220 TLS go ahead
Connection failed. Error #2: stream_socket_enable_crypto(): Peer certificate CN=`server12.thulo.com' did not match expected CN=`smtppro.zoho.com' [/home/dlabsart/public_html/crm/application/vendor/phpmailer/phpmailer/class.smtp.php line 374]
SMTP Error: Could not connect to SMTP host.
CLIENT -> SERVER: QUIT
SERVER -> CLIENT: ?k?^??]?|?O?BS?+Uu???o?:221 server12.thulo.com closing connection
SMTP ERROR: QUIT command failed: ?k?^??]?|?O?BS?+Uu???o?:221 server12.thulo.com closing connection
Connection: closed
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

question from:https://stackoverflow.com/questions/65905513/how-to-solve-smtp-connection-problem-in-perfex-crm

Answer 1

This one's pretty self-explanatory, but there's not much you to my knowledge can do about the error you're getting:

Peer certificate CN=`server12.thulo.com' did not match expected CN=`smtppro.zoho.com'

This indicates a certificate mismatch issue - the SMTP certificate verification for the TLS connection did not match what was expected and therefore you have an "Invalid Certificate" problem - in Firefox or Chrome this would be "The certificate does not match the domain/url".

This is an issue with the SMTP side of things, on the remote servers you're connecting to, and it may be something you have to talk to Zoho about for properly configuring this; if Perfex CRM has an option in its SMTP settings to ignore invalid certificates then that's your workaround, but it's a very insecure workaround.