Cannot send or receive mail after comcast blocked port 25

Recently Comcast/Xfinity blocked port 25 on all residential connections. Since that time, I have not been able to send or receive email from/to any external addresses. I can still send email to my own domain users both inside and outside of the local network. Is it possible to change the port that the server sends outgoing email? The reason is because in my logs when sending to outside address (i.e. @me.com or @comcast.net), the logs state 'No Route Found'.

My next question is would my ISP blocking port 25 affect my ability to receive email as well? I know that comcast blocks port 25 inbound and outbound.

Thank you, in advance for any help.