What is DIRECTDB.DLL?

For the past week, when I try to open my e-mail, it will go so far and then error comes up with this. DIRECTDB.DLL No one can tell me what this is. It will shut down my e-mail. When I try again, it cont. to download prior e-mail to where I have 9 of each e-mail, no new e-mail, and can’t do anything with what I have. I can’t erase, move or open. Someone PLEASE HELP ME, PLEASE
Sincerely
pjprierspurry@bolt.com
Patti
P.S. This e-mail works, it is my home e-mail that doesn’t