Justin at Palmer Web Marketing has compiled a handy list of tips on improving email deliverability - an ongoing challenge for marketers, especially as webmail providers introduce new filtering systems and consumers become more inclined to hit the 'spam' button.
Here's a selection....
Remove inactive subscribers
While this will obviously shrink the size of your database, inactive subscribers are most likely to report emails as spam.
Consistent address information
Using the same email sender name and address will not only mean more readers recognise your brand, it will also spare them the inconvenience of adding new senders to their webmail address book to ensure deliverability.
Use double opt-in
This is best practice for many ISPs, but is best for customers too, as it ensures that they are expecting your emails. It also has the added bonus of removing misspelled email addresses from your database.
Prominent unsubscribe links
If customers cannot find this link easily, they may well unsubscribe by using the spam button. TradeDoubler, for instance, runs this risk by not having any unsubscribe link at all in its email newsletters. Justin recommends placing it at the top of the email where it can be found within seconds.
Send emails at consistent times
Sending emails on the same days and same times tells ISPs that you are a responsible email marketer, rather than a spammer. Email frequency is also an issue here as sending emails too often can annoy customers into hitting the spam button.
This is important, as sending emails again and again to invalid addresses will set alarm bells ringing for many ISPs.
Make emails relevant
If emails are irrelevant, customers are more likely to label them spam.