To make sure somebody's mail is never found there, you can add the sender -- or complete domains -- to the white list of known email sources in Lockspam. I have whitelisted the "about.com" domain, for example, to make sure Lockspam never files my About newsletters as spam.
To add a sender or domain to the Lockspam whitelist:
- Select Lockspam | Options... from the Lockspam toolbar.
- Go to the Whitelist tab.
- Click Add.
- Type the email address or domain you want to whitelist.
- To whitelist a complete domain, precede its name with "*@".
- To whitelist all About newsletters, for example, type "*@aboutguide.com".
- Click OK.
- Click OK again.

