A phishing email has been going around for about a month now. In most instances, if you have gmail, hotmail, yahoo, etc then it is going to your spam folder.  But just in case, if you get an email that says your federal tax payment has been declined – ignore it!  The IRS does not email individuals to let them know anything about their tax payments.  In addition, by mailing your 941s and estimated tax payments certified mail, return receipt requested and paying by check, you can have proof of mailing (the stamped certified receipt), proof of receipt (the returned green card) and proof of payment (the copy of the cashed check from your bank.