Windows 10 Outlook 2016 Mailbox Full?

[BudVitoff]

Running Outlook 2016 under Windows 10.

Everything was running smoothly when all of a sudden a couple of weeks ago, we started getting the error message "554 5.2.2 mailbox full" and we could not send any messages. We discovered that although the system implied that the recipient had the full mailboxes, it was really our own system that had the problem. We trimmed everything of ours down to ridiculously low levels but that didn't happen. Just in case, we did the same for our recipient, but that didn't help. We even emptied the Recycle bin thinking that deleted files didn't actually make space available until we did that. More research indicated that our server saves deleted files for some time and it filled up its space, or something like that. So we've hit a wall and can't get past it.

Any ideas?

 

[Neemobeer]

Just to be clear, did you delete items from the 'deleted items' folder? Deleting them once just moves them to above mentioned folder. You need to remove them from deleted items to actually delete them from the server