554 5.7.1 Your mail could not be delivered because the recipient is only
   accepting mail from specific email addresses. If you feel you received this
   in error, please contact the recipient directly and ask them to check their
   email settings. (in reply to end of DATA command)

I keep getting the message below when I send an e-mail to an AOL account. It just started yesterday. I haven't changed anything, nor has the recipient of the AOL addy. It goes thru just fine with IE, but not Firefox. How can this be remedied? *** ATTENTION *** Your e-mail is being returned to you because there was a problem with its delivery. The reason your mail is being returned to you is listed in the section labeled: "----- The delivery status notification errors -----". The line beginning with "Diagnostic-Code:" describes the specific reason your e-mail could not be delivered. The following lines contains the RFC822 header of the original email message. Please direct further questions regarding this message to your e-mail administrator. --AOL Postmaster ----- The delivery status notification errors ----- <xxxxxxxxxx@aol.com>: host core-dke003a.r1000.mail.aol.com[172.29.215.88] said: 554 5.7.1 Your mail could not be delivered because the recipient is only accepting mail from specific email addresses. If you feel you received this in error, please contact the recipient directly and ask them to check their email settings. (in reply to end of DATA command)