email bounced (failing for a long time(and retry time out not reached))

Question

hi i have XGS4300 (SFOS 19.5.4 MR-4-Build71), it is MTA mode, today i start getting bounced email while sending email to few domain 
 R=default_mx_router T=remote_smtp: all host for 'mahagenco.in' have been failing for a long time(and retry time out not reached) 
 can you please guide how to resolve this issue.

Erick Jan · Answer

Hi, 
 Thank you for reaching out to Sophos Community. 
 For initial troubleshooting, kindly try to telnet to that host directly from the Sophos Firewall. 
 Check the DNS to see if it resolves to the said sites, and verify the MX records to see if they are configured correctly and pointing to the correct mail servers. 
 Look at the logs for further details ( awarrenmta.log) 
 You may also check the following KB, which might assist you. 
 
 Sophos Firewall: MTA troubleshooting guide 
 Sophos XG Firewall: Mails failed to deliver due to retry time not reached for any host