emails not received/disappeared

[#1]

Using Thunderbird with Freenetname as my address - noticed last night that no emails had been received since 1100 in the morning, and then this morning still this same. Able to send out to secondary account (gmail), but sending back to freenetname were not received.  Also checked by logging into plusmail - no new emails there either (including the test ones I had sent to myself).

Then suddenly started receiving emails exactly 24 hours after last one received, but none at all that were sent to me, including test emails, during that 24 hours - a black hole has appeared in my system.

Any ideas as to what is going on?

[#2]

Then suddenly (at 1130) some, but not all,  of the missing emails appeared

[#3]

....And as time goes on even more keep appearing at random intervals and in random order - latest two to arrive were from yesterday midday and today at 1030. Anyone know what's going on?

[#4]

Those legacy email brands have a storage limit of 250MB. Is the mailbox full?

[#5]

And another black hole appearing - no emails in since 1200 yesterday, although outgoing fine.

Townman - thanks for the info re mailbox size. I have had no problems with the size  of the mailbox over the years  I have been using Thunderbird/Plusnet/Freenetname, although I have now reduced the size dramatically.

[#6]

Have you checked the SENT ITEMS folder?

After 'deleting' from the inbox (and other folders) you need to empty the trash folder!  Many people are not aware of this.

[#7]

Townman,

I may owe you an apology. 

About three months ago my long serving computer decided to trash the motherboard along with two of my four hard drives , which were the ones with all my Thunderbird files and settings on (including emails going back nearly 20 years!). Despite my best efforts I was unable to recover any of them, and bit the bullet with a new machine and started the process of setting everything up again. It would seem that somehow I have changed my inbox settings from POP3 to IMAP. thus the plusnet webmail inbox was now storing all those I had received and was probably full.  I have now deleted 99% of them, but the system appears to have gone haywire. None of yesterdays emails (post 1200) have come through to Thunderbird, and only three of today's, but not in any order.

Now I'm trying to find what/where I have changed a setting, but at the moment I'm getting really confused and can't find anything with IMAP enabled.

Many Thanks

Shackman

PS - just read your reply re sent mails - I've deleted those on my plusnet webmail as well, and am now going for a sit down in a darkened room!!