以下為常見的錯誤訊息 :
1. 寄件者的郵件伺服器被列黑名單
JunkMail rejected - ti-224-238-89.telkomadsl.co.za [105.224.238.89]:30118 is in an RBL, see

http://www.spamhaus.org/query/bl?ip=105.224.238.89

2. 驗證寄件人身分無法完成
Could not complete sender verify

3. 收件者電子郵件帳號並不存在
SMTP error from remote mail server after RCPT TO:: host gmail-smtp-in.l.google.com

[74.125.28.27]: 550-5.1.1 The email account that you tried to reach does not exist. Please

try 550-5.1.1 double-checking the recipient
或者是
No Such User Here

4. 被判定為垃圾郵件
Message filtered
發生以上錯誤都會導致信件傳送失敗，如果有查看到其他的錯誤訊息
請來信至技術支援提供給我們錯誤訊息，以便幫您查詢傳送失敗原因