message+ protocol

[ukkmr]

I am using Message+ on both Window PCs and Android phones.  It works fine when I directly connect to the Internet on the incoming internet line provided by Optimum to my house.  However if I connect after my microtik  router it no longer is able to synchronize (all devices).  This router has no problem with regular Skype voice, internet or outgoing VPN connections so the problem is presumably  specific to the protocol.  This router is providing SRC (and dest NAT).  To debug this I would like to know what protocol and ports are used by Message+. 

I'm assuming it be handled via SRC NAT.

thanks

Keith R

[ukkmr · Accepted solution]

Wireshark shows Message+ uses a very straightforward IMAP protocol connecting to messages.vma.vzw.com.

The reason I had a problem was a overly broad destination NAT rule I had added the rule to allow external access to my own IMAP server.  The rule was causing the outgoing IMAP request to be bounced back to this internal server.

Probably too specific to be of general use but I thought I'd post just in case it helps someone else.