If I deleted the rejection letter that has my code what can I do?

[ladycoconay]

How can I retrieve a lost rejection code?

[xmasbaby0]

If you deleted an email it is gone unless it is in your "Trash" bin and you can get it back.  Most rejections are for incorrect AGI.  If that was the reason your return was rejected:

https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947

https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/00/270...

Your 2018 tax return shows your 2018 Adjusted Gross Income (AGI) If you filed a joint return then the AGI is the same for each of you.

Form 1040        line 7

If you are using the same TT account that you used last year, you should also be able to find this number in your Tax Home for 2018

If entering the amount from your 2018 tax return does not work, then try entering “0” instead.  If that does not work and you still cannot e-file, then print, sign, and mail your tax return.

You can get a free transcript of your past return from the IRS: 

https://www.irs.gov/individuals/get-transcript

Note: If you filed late or amended your return, your correct 2018 AGI may not be in the system.

https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online

Note:  If you mail your federal return, you will also need to mail your state return.  You will not be able to e-file your state return.

https://ttlc.intuit.com/questions/3415597-what-if-i-entered-the-correct-agi-and-i-m-still-getting-an...

https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online

If your return was rejected for a duplicate Social Security number, you cannot fix that.  You have to print sign and mail your tax return.

If you used the non-filer site to get a stimulus check:

We are seeing people who did not notice or ignored the warning on that site about using it if they would be filing a tax return.

https://ttlc.intuit.com/community/tax-topics/help/stimulus-how-to-file-your-return-after-getting-rej...

[Opus 17]

It doesn't matter any more.  It is too late to re-e-file a rejected tax return.  You will need to print your return and mail it to the IRS, don't forget to also print and mail your state return to your state.  Fix the error if you know what it is, before you mail your returns, if you can.  If the rejection reason was something minor, like a wrong birthdate, the IRS will process your tax return anyway.  If it was something important, the IRS will contact you for more information.