my Windows 10 updated but now I cannot SEND via my email client (thuderbird). It gives me an error message. I can send a screen shot if need be.
I can send a screen shot if need be
Please never wait to provide essential information. You always have an advantage (no need to wait then provide than wait again) when give every bit of useful info (LO version; detailed OS version; Thunderbird version - all including architecture (32- vs 64-bit) and build numbers; screenshots; whatever else you might think about).
Edit your question and upload your files, please. (Shreenshots)
What version of Thunderbird are you using?
This is a known Thunderbird issue and is fixed in 60.5.3 (released 5th March 2019).
@BigRAl: the issue with TB 60.5.2 (which I introduced btw) is not something related to “my Windows 10 updated” 
@mikekaganski: clearly it is, see, for example, this issue on SUMO. I have been following many such SUMO posts in the last few days.
In addition, updating TBird fixed the OP’s problem.
In addition, updating TBird fixed the OP’s problem
true - that answers all. Still, the issue you cited was not “Windows 10 updated” - rather that was “my TB updated”, no?
The TB update was caused by our MAPI work there; and unfortunately, there was a long-standing issue with TB updater, which didn’t properly update MAPI DLLs - but since there was no changes in those DLLs lately, it was only discovered due to our changes.
I hope that when we push 16-bit MAPI changes soon, that won’t cause similar problems.
you are right…updating Thunderbird to 60.5.3 appears to fix the issue…thanks, Gene