Email Problem

[500e]

Have a problem with Gmail acc
Using Thunderbird some emails come through, also use a ***duck.com that is routed to the gmail acc, some of the duck comes through but most do not.
Drivong me mad, going to Gmail server they are all there it would appear there is a glitch in Tbird
Any Ideas

 

[MoreWellie]

Not specifically gmail I have noticed that messages marked as read in other devices don't trigger the tbird filters

I do use gmail accounts in it but don't read those messages anywhere else so it may be related