Customers don't get password reset email

My customer forgot his password and his purchase cannot be processed. He requested a password reset but did not get an email.

How can I fix this issue?

Thanks,
Daniel

What has been done to validate that this is an issue with multiple recipients and not just this one? Are they able to setup a different account with a different email, are you able to test the condition using an email through their same "host" (Google, yahoo, etc...)

What are your email settings? (don't give credentials). Seems there is a FAQ about customers not receiving emails or and this does exist, about email troubleshooting. Might suggest reviewing one or more such FAQs$

In addition to mc12345678 comments.... If you install email archive manager

It is easy to see if zencart has transmitted the password reset email. You can also see the password sent just in case you want to test it for the customer. Copy/Paste works more reliably than manually entering the password.

The usual cause is using "PHP" as the transport method instead of SMTPAUTH.

Ref:
http://www.zen-cart.com/wiki/index.php/Troubleshoot_-_Email_Problems
http://www.zen-cart.com/wiki/index.php/Troubleshoot_-_Understanding_Causes_Of_Lost_Emails