Mailbox unavailable in c#

Question

Hi, In my mail sending functions, sometimes I got the below exception. "Mailbox unavailable. The server response was: 5.1.1: Recipient address rejected"

Thiyagarajan E · Answer

Hi, @Sreekanth & Madan I am getting the exception, not only for a specific user. The exception occurred 15 - 20 times a day for different users. after some time it's working properly for the same user.

Rajeesh Menoth · Answer

Hi, Please check your code and go through the smiliar threads. Reference : https://stackoverflow.com/questions/3528262/send-many-mail-problem Translate to english !! https://social.msdn.microsoft.com/Forums/sqlserver/it-IT/fad976c5-3d4b-42f6-8e15-a7804791111d/errore-invio-mail?forum=aspnetit

Sreekanth Reddy · Answer

Hi Thiyagarajan E, There might be 2 chances. Either sender mailid is wrong or recipient(recievers) mail ID might be wrong. Please confirm the mail id is exists or not. If it helps accept as answer. Else come up with your query. Thank you.

Madan Shekar · Answer

If you receive a user unknown bounce, and you have checked to make sure the address is correct, the next thing you should do is try to contact the person you were trying to email by other means. Frequently, people are not aware that they are bouncing email until someone else tells them. Also, do not delete the bounce message. It can help the user and their ISP resolve why they are bouncing mail more quickly. If you do not have other means to contact the person who is bouncing mail, you probably have a dead email address. Try mailing them one more time (preferably at least a day later) in case it was a technical problem, but after that, stop using that email address. If you run a mailing list, and one of your subscribers starts bouncing mail with this error, remove them from the list.