Squirrelmail question

[#1]

Hi,
Email is causing me, a little, stress and tension that I could really do without!
Some while ago PN used to host my own domain name which was nice but just not working really well, (spam and security issues) so I moved my domain to another host 
Because of that I have no real use for Squirrelmail at all. Frankly my whole PN user experience would probably improve if PN would simply forward all of my email to my own domain name address.
I used to login to webmail using
1) username+postmaster
2) username+anothername
which worked quite well as mentioned above; apparently something has changed and now I login using just my username, as neither of the previous login options work any more.
Ordinarily this still does not cause me any problems and I sleep well at night!
I tested my PN username email account from my gmail account this morning to see if it was receiving email, then logged into webail using username and sure enough there was my test email.
Then I thought ok I will now disable MySql, give it a minute or so and then re-enable it and subsequently check webmail to see what password I have been granted to use in MySql. That was at least 30 minutes ago, I see nothing from PN about MySql and my prior test message has vanished from my email account. Is it just me?
Can some kind support person please suggest a resolution, like forwarding ALL PN email to my hosted domain.  If that is not possible please email the new MySql password to me using my externally hosted domain name email address.
Thanks

/endrant 

[#2]

Do you have an email client that is still picking up emails from your default email account. If so, that will have deleted the email you saw in webmail when it was downloaded.
Do you actually have separate mailboxes (not alias or forwards) for postmaster and <anothername>? If they are aliases then any email for it will go into the actual mailbox it is an alias for.
You can see your mailbox setup via member center under Email Settings -> manage my mail

[#3]

Hi Peter,
Thank you very much for your help. You were correct, I had created a mess of my own making. I have now started on my web site; it will probably not be all that long until I need some more of your valuable assistance.
Thanks again.