Fix my sharing files portal site

Hello
I need a programmer to look at my sharing portal site, couple of issues I have with it its not sending out mails when it should and I would like the password system upgrading from emailing out the password to a link in the email sending you to fill out your password on the portal site itself
There will also be ongoing maintenance with this site, The portal was written 3 years ago and has run pretty solid for this long too, there is live data that cannot be changed but the guy who wrote it did changes to the system keeping all the old data in tact, unfortunately the programmer who wrote it is not available any more and I need to find someone new to take on his role
If you have any questions please ask
Regards
Michael