First of all if your personal email has your name then a secondary one with the reason for its use should contain its name. Example
Dawnscoupons@ blah.com for example.
That way its kept more organized. Second this to try and do is make shore your browser saves the email address and password. But make shore your the only one that can access this. For example have it on only your pc or your user account.
I have firefox make shore it remembers all my email accounts even for loging into yahoo mail.
I also keep a autofill addon set up on my firefox. For filling out samples and freebies and forum sites.
I also use filters for specific email accounts.
For folders titled coupons,samples,received. And then one for forums.
That way if you receive the item place all the emails from the items you have received in the received folder. And make shore you keep a list of the items never received. After all why fill out for the same thing over and over again.
Filters and folders are the best way to go. Plus installign the yahoo toolbar and making shore you have the mail button on it will also help with knowing when you receive emails.
Plus by using mail in windows helps also.
I have my gmail and yahoo both set up in there.
I hope this helped.