It’s time for an e-mail check up. E-mail Doctor gives loads of free advice about e-mail marketing, including some interesting tidbits:

• Plain text e-mails are more effective than HTML e-mails. More >
• The “from” line most often decides whether or not a user will open the e-mail. More >
• Most subscribers give a throwaway e-mail address instead of the e-mail address they actually use (includes tips for getting that real address). More >