One of the streams has already been used and can't be reset to the origin.

 

在透過C# SMTP API寄發信件通知時候

若有附件

這時候若處裡不當

就可能拋出這個例外錯誤

Before

由於例外發生在

Attachment只要SMTP使用完後做Dispose也會連動將MemoryStream給清空

因此應放置於迴圈內每次初始

After

Ref:

SMTPException One of the streams has already been used and can't be reset to the origin

https://stackoverflow.com/questions/33342212/smtpexception-one-of-the-streams-has-already-been-used-and-cant-be-reset-to-the