This question is not 100% technical. I've looked online and I couldn't find this being discussed.
We have a forgot username feature in our website which mails the username to the user's email address, using our own mail server. We also put a message in the web-page asking the user to wait for 20 minutes for the mail to arrive since there can be occasional delays.
Our business tester raised an interesting point saying that 20 minutes seems an unacceptable time to ask the user to wait for. He said our technology should send emails immediately and the maximum lag should be 1 minute at worst.
Firstly, emails are usually received immediately by the recipient so there isn't a problem there. But in our experience in using other websites, sometimes emails do take a while to arrive. I also remember reading somewhere that emails (at a network level) use a lower quality of service QoS unlike voip services. I can't seem to find it now. Users can also experience delays in receiving emails because of issues in their own mail server.
Now, all we can do is send the mail using our mail server and ensure that the load and resources on the server is well managed. 1) Is there anything else we can do to ensure that our mails are sent quickly at all times. 2) What is the acceptable time, we can ask the user to wait until he logs a call with help-desk? I believe that there can be lags at a network/protocol level and the user's mail server which we can't do anything about.
Thanks.
