• When you upload users from a file and tell Moodle to create a password if needed, Moodle creates a empty password field in the database that it fills when the cron.php is next run (at whatever frequency you set it to run)

• When you delete a user in Moodle, their username is replaced with their email address plus a short random number and their email address is replaced with a long random number that looks a bit like a password hash.

The problem is:

I upload users, Then for some reason, I deleted the users. The next time the cron runs, the new password is sent to the long random number, so I am getting this messages:

The original message was received at Fri, 29 Jun 2012 07:30:05 -0500
from XXXXXXXXX@localhost

----- The following addresses had permanent fatal errors -----
5afb9bcb73acf95a28aa35dbd9acdbda
(reason: 550 5.1.1
<5afb9bcb73acf95a28aa35dbd9acdbda@cloud2.XXX.net>... User unknown)
(expanded from: 5afb9bcb73acf95a28aa35dbd9acdbda)

----- Transcript of session follows -----
... while talking to [127.0.0.1]:
>>> DATA
<<< 550 5.1.1 <5afb9bcb73acf95a28aa35dbd9acdbda@cloud2.nivel7.net>... User
unknown
550 5.1.1 5afb9bcb73acf95a28aa35dbd9acdbda... User unknown
<<< 503 5.0.0 Need RCPT (recipient)

– Forwarded part –

The original message was received at Fri, 29 Jun 2012 07:30:06 -0500
from XXXXXXXXXXX@localhost

----- The following addresses had permanent fatal errors -----
aa466f29a42582d133bc36c9a227c118
(reason: 550 5.1.1
<aa466f29a42582d133bc36c9a227c118@cloud2.nivel7.net>... User unknown)
(expanded from: aa466f29a42582d133bc36c9a227c118)

----- Transcript of session follows -----
... while talking to [127.0.0.1]:
>>> DATA
<<< 550 5.1.1 <aa466f29a42582d133bc36c9a227c118@cloud2.nivel7.net>... User
unknown
550 5.1.1 aa466f29a42582d133bc36c9a227c118... User unknown
<<< 503 5.0.0 Need RCPT (recipient)

.............

Moodle still try to create a password (for any account with no password) even if the user's account was set as deleted