Due to intermittent connection with internet resulting from Degradation of Service on our VSAT, we constantly have problems sending emails. In addition, there are few minor reasons why email sending fails. So this blog is meant to give guide to those who have problems sending emails.
Reason: Invalid email address(es). Users kept telling me that their email is not delivered properly. And I kept telling them to check the email addresses because if you have more than one recipient or have some more on CC and BCC, a single invalid email will give you that undeliverable error report.
Solution: Confirm that you have the proper email addresses.
Reason: Dangling Reference - Because email sending is taking the user so much time, the tendency is they will close Outlook, Open it again, then try sending the email once more. They may repeat doing this but got no luck. The reason is (per our experience on several units here), there are dangling references of outlook in the system processes.
Solution: Right-click taskbar, activate Task Manager, Click Image Name Header to sort the processes alphabetically either ascending or descending, and kill all Outlook instances there. Ensure that there is no more outlook instance before reopening outlook again. I am not sure if this is a bug of Outlook 2007 or not but that happens.
Reason: Add Ins. For some more reasons, some add ins affect also the way how outlook works smoothly.
Solution: Open outlook in Safe Mode. Few users know about this feature. You can easily do this by pressing Ctrl button while clicking outlook. It will inform you that it has detected you pressing the Ctrl key and will ask you if you want to start outlook on Safe Mode. Click ok then try sending your email again.
Reason: Blocked outgoing port. In some cases, you may not know that your unit is spewing out SPAMs due to undetected malwares on your unit. When this happens, your ISP may block your outgoing port (default is 25) and you won't be able to send out email.
Solution: Try the alternate port 587. Click on Tools, Account Settings, double-click your account, More Settings, Advanced, then change your outgoing port (SMTP) to 587.
Reason: Your recipients admins has made some protection on their end against SPAMS. When attempting to send an email, you may see either a relay error stating, Relaying Not Allowed, or an alert box requesting you enter your password. This would be an indication you need to check Outgoing SMTP authentication on your mail client program.
Solution: To avoid the possibility of your email being treated as SPAM, ensure that your email is authenticated by your Outgoing Mail Server. To do this: On outlook, click Tools, Account Settings, double-click your account, More Settings, Outgoing Server Tab, tick My Outgoing Server requires authentication, Log to Incoming Mail Server before Sending Mail.
Well, that wraps up the way I troubleshoot our sending of emails problem over here. If I suddenly think of some more reasons and the ways to counter those, I will update this blog.
Hope this helps!