Allow Outlook Ports Only

hello everyone

iam trying now sophos xg for evaluating it to deploy it in my work environment

so iam testing every single policy and iam having a problem to get one of them into action

we have a cloud mail services

with standard POP3 port which is 110

and custom SMTP port which is 55521

for the policy iam trying to make is disable internet access to all users but they can use outlook only

this is my steps

created new service for the SMTP with ports TCP/UDP 55521

then i created a new services group and added services (DNS, POP3, Custome SMTP) and named it "Web Access"

finally i created a rule

Action = accept

Source Zones = LAN

Destination Zones = WAN

Source Networks and Devices = Any

Destination Networks = Any

Services = Web Access

unchecked Match known users

but i cant send any email although i can receive emails with this policy

so any suggestions for what i have done wrong ?

and here is a screen shot of my rule

thanx in advanced