I have a few websites that run Joomla and send some notification emails via Godaddy SMTP server smtpout.europe.secureserver.net. Godaddy only allows 250 SMTP relays per day for free, but for this particular purpose this was more than enough.
One day I noticed that I was not receiving all notification emails I was supposed to receive. First of all all I logged on to Joomla's administration panel and tried to send some test emails using Joomla's built-in Mass Mail functionality. Results were interesting - most of the time emails would go through, but around 30% of the time sending would fail with error:
This was affecting all my Godaddy email addresses (I had 4 at that point, all on different domains).
To make sure that the issue is not hosting or ISP related, I setup one of the affected SMTP accounts on my local PC in Microsoft Outlook 2010 email client. Results were identical - around 30% of attempts would fail. There was no particular error message - Outlook would simply prompt to re-enter username and password for the smtpout.europe.secureserver.net server.
Internet E-mail - Enter your name and password for the following server.
This would normally mean that either username or password was rejected by the server. To be completely sure I captured SMTP traffic with WireShark. The crucial bit was here:
Here is a successful example:
235 Authentication succeeded.
What this meant was that Godaddy's SMTP server one time would accept, another time reject exactly the same username and password combination. This was the time to contact Godaddy's tech support.
After going through some basic troubleshooting steps, Godaddy support guys checked server logs on their end and could confirm what I was seeing - the server would either accept or reject the same credentials without any apparent reason. Unfortunately they had no idea why this was happening...
After speaking to couple of technicians and trying few random things, such as changing email account password, one support guy suggested deleting the email address completely (via Godaddy's email admin page) and then to re-create it. I was very skeptical, but to my surprise this seem to have resolved the issue! The support technician said that this often helps with similar issues, which suggested that this wasn't an isolated case.
That day I couldn't reproduce the issue anymore and was ready to write this down to one of these unexplained IT mysteries. Unfortunately this wasn't the end...
Next day I run some more testing and found that occasionally emails get rejected again! This time MS Outlook would report following send/receive error:
This didn't sound right for two reasons: first, there was no way I could have sent over 250 emails on that day. Second, the issue was completely random - sometimes emails would be sent, sometimes they would be rejected with above error.
To confirm that I haven't exceeded my SMTP quota I went to my Godaddy's email account page and found following:
Messages sent today: 5/250 (SMTP relays)
At this point I decided that this was enough and I wouldn't waste more time trying to fix this. Even if it could be resolved by doing something random, like as re-creating email address, I was simply not willing to trust temperamental Godaddy SMTP servers anymore.
I spend few hours transferring all my email accounts from Godaddy to HostGator (where I had some shared hosing sites), but it was well worth it. SMTP service on HostGator servers has been rock solid so far.