What is the UID of a Outlook email

[Texsolly]

I have been using Outlook with AOL as ISP for few years no with no trouble.
this last week whenever I open or send an email I get a pop up message that
states the UID of the mail has suddenly changed. Closing the window reveals
the mail to be open or sent it's just getting annoying that this message
window opens up everytime.

 

[Brian Tillman [MVP - Outlook]]

I have been using Outlook with AOL as ISP for few years no with no trouble.
this last week whenever I open or send an email I get a pop up message that
states the UID of the mail has suddenly changed. Closing the window reveals
the mail to be open or sent it's just getting annoying that this message
window opens up everytime.

It's a unique value assigned to a message by the server. AOL did something to
cause the UIDs to change. Outlook notices the difference and tells you. You
should be able to fix the problem by deleting the IMAP account, stopping and
restarting Outlook, and re-adding the account.