Change email login to another id
3652
How do I change my login provider(s)?
56931
Apex email : How to override 'From address'
134069
Can I receive the newsletter under a different email address?
113339
Use Windows Live ID, but login with a different password
18092
How do I change the email address associated with my Stack Exchange OpenID?
101538
Changing From Email Address in SharePoint Designer 2010 Workflows
116267
Change user for automatic login
145944
How do I change a username? (shortname and home folder)
125103
Transferring domain to new host, but keeping email on old host
120729
Add log in link to menu in Twenty Twelve
27216
How do I remove an OpenID or login?
51293
Reset IDENTITY value
62560
Change Password Programmatically
27095
Always logged in with OpenID, how do I create a password for my account?
52627
Change default user for authentication
104231
Can I change root's email address or forward it to an external address?
83096
Send from Gmail with another email address as the Reply-to or From address