I mailed in my tax return in Sept. after filing an extension to the address stated in the form. Why did I get a letter saying that there is no record of a tax return?

[maelin]

Address on return form:
Department of the Treasury
Internal Revenue Service
Fresno, Ca 93888

letter stated: On November 11, 2020, we received a request for verification of non-filing of
a tax return.
As of the date of this letter, we have no record of a processed tax return
for the tax period listed above.

[Critter-3]

Simple ... the 2019 return has not yet been entered into the system or processed yet ... due to the covid shut down earlier mailed in returns are taking 4 months or more to process completely.  

[Carl]

Apparently, someone, probably you or another in your household, requested a letter from the IRS verifying that you did not file a tax return for 2019. The IRS responded stating that as of Nov 11, 2019 they have no record of a tax return. That's it. Nothing more. Nothing less.

Since the IRS is months behind in processing returns, it would seem apparent to me that they just haven't gotten to your 2019 tax return yet, is all. Therefore, as of Nov 11th they have no record. That does not mean they did not receive your mailed tax return. It only indicates that they haven't gotten to it and processed it yet as of the date stated in the letter.