At the current time, a Sophos UTM does NOT ship with port 587 listed as a valid SMTP port for email sending. If you need to add this port, these screenshots will show you how to add the port:
1. open your firewall web admin:
Open your UTM appliance’s web admin
2. type ‘firewall’ in the search box:
search for firewall in the search box
3. look for the email messaging rule in the firewall definitions :
look for the email messaging rule in the firewall definitions
4. open the ’email messaging’ firewall rule and click the definition name:
open the ’email messaging’ firewall rule and click the definition name
5. click the little green + symbol, add your definition for TCP port 587 and save :
click the little green + symbol, add your definition for TCP port 587 and save
Voila! You have added port 587 as a valid SMTP port to your Sophos SG Series UTM.
Notes: this tutorial was done on SG firmware 5.3.10-11 (the very latest available at time of publishing) – if you have a different firmware version, the steps may be slightly different.