v18: mail over port 587 not being delivered

Question

Today i upgraded my XG 17.5.9 to XG 18.0.0. Optimized and cleaned up all the migration rules. 
 Now everything seems to work fine except for one thing. The mailserver i am using cannot connect to a relay host on port 587. The message it returns in the log is "Status: 5.7.0 538 5.7.11 Encryption required. Please reconnect with TLS enabled." 
 I've checked the knowledge base but am not able to resolve this. Hope anyone has any ideas to help me. 
 Thnx, Peter-Paul

KingChris · Accepted Answer

Hi Peter-Paul Gras 
 Please run command from console: console> show service-param and PM me the output. 
 Also double check to see if adding your relay mail server to the "skip TLS" list to see if that helps. 
 If all else fails, I would suggest to open a support request if you have a valid license and are not a home user. 
 Thanks!

Peter-Paul Gras · Answer

I added the mailserver to the TLS exception list. (added a new fw rule to scan HTTP/HTTPS traffic from this server using proxy HTTPS scanning) 
 Everything working as expected. Thank you all for your ideas and help, much appreciated! 
 Grtz, Peter-Paul