First, I'll apologize in advance if this has already been discussed. I'm currently running MWP 7.7.0. I have three email accounts configured using POP3. Two to my ISP domain and one to Xfinity (Comcast). No Gmail (Inbox), Yahoo, Hotmail (Outlook).
On my Android phone and my Windows 10 PC using the Outlook client, I have all three setup for IMAP.
What I'm seeing is the following:
Email clients on Android/Outlook no issues. I can see the same email messages. If I delete a message from either device, it is reflected on the other. This also includes the web clients. However, on MWP, it continues to see the message(s) and I have to manual remove it by selecting, then washing mail. I also noted that if a delete the email from MWP, it appears to only do so on MWP because the message shows up on my Android/Outlook clients.
Xfinity recently enabled IMAP so I decided to reconfigure MWP from POP3 to IMAP on all three accounts. The email list refreshed and matched what Android/Outlook see. However, when I select an email for removal within MWP and hit the Wash Mail button, nothing happens. When I set everything back to POP3, the email is deleted from MWP.
Okay, hope all that made sense. I suspect it's something on my end. I'm currently back to my original configuration. Android/Outlook, IMAP and MWP, POP3.