最近用gmail時發現有幾封不能寄，
是顯示：
Delivery to the following recipient failed permanently:
****@********.tw
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for
the recipient domain *******.com.tw by parmail1.fr.publicisgroupe.net.
[81.200.177.120].
The error that the other server returned was:
550 #5.1.0 Address rejected.
我查了一下是SMTP Error，
不過我不了解這是什麼；
也有說是對方將我加入黑名單，
但我不是寄廣告信，之前也沒發過信給她，
但我不知如何修改，請問要怎樣才能寄信．
謝謝^^