I have two shaw.ca email accounts. I can receive an email from someone outside shaw on one address but not the other. It doesn't show up in junk. I don't have any rule that handles it automatically. I don't appear to have this problem with any other email (but now I'm worried I might). The sender doesn't appear to have this problem with any other recipient (but who knows, maybe that's where the problem lies).
Any suggestions on how to debug/resolve are greatly appreciated.
(edit1) P.S. My config, if it matters:
1. I use a PC/mobile client to access my emails, via an IMAP setup
2. I have Thunderbird on two computers and Bluemail on my phone
3. I've checked all of them and don't find the "lost" email
(edit2) P.P.S I also checked the webmail client and no email there, either, so I guess its more likely that the problem is with the sender.