MyBB Community Forums

Hi,

I run bankofamericasucks.com and its obviously a big spam target. I have one spammer who posted 1000 posts in a day. I deleted his account but all the posts stayed now I am not able to delete those 1000+ posts. 

How do I cleanup this mess?

instead of deleting spammer account you should have used purge spammer button !
anyway, see replies at this thread => deleting mass spam posts

The issue I have is the account is deleted so there is no way to know the UID at this point

Do you know their username?

Yes, but its deleted so there is no way to look it up by username

putting the forum behind something like cloudflare and/or incapsula (both have free tiers) should help eliminate a lot of the spam.

Yes when you delete the account the threads stay and you manually have to delete the threads.
If you see no purge button then it means you have to increase the post limit.
Configuration > Purge Spammer
Then you will see the purge option.