Why Email sent with an attachment is not delivered or bounces back?

Posted:  July 14th, 2016

These are some of the reasons email with an attachment is not delivered or bounces back.

1) If the size of the attachment you are sending is 10MB or larger, as a consequence of the  size, the mail will probably be rejected or not delivered. In other words, you may be sending the recipient an attachment that is too large for their mailbox capacity. If that happen, there will be some text that states that the message size exceeded the fixed maximum message size.

2) Some servers are configured to block most attachment types if they are not zipped up. A few of them being blocked are... .pdf .src .exe the reason for this is that your mailbox would be flooded every day with viruses if this was not in place. A few attachments that are fine without zipping up are .gif .jpg .html unfortunately there is no way to turn this off so your only option is to zip your attachment .

3) If your mail server has been blacklisted for spamming, then your email might bounce back as well. In that case there will be a clear message stating so.