a. Tidy up your email list into different segments eg, Paying customers, New customers, Small Medium Business. This is because different messages will be applicable to different audience.
b. Use sender score to make sure that sending reputation of your e-mail server is good.
c. Use DNSStuffs.com to make sure that your IP address for e-mail sending is not being blacklisted.
d. Send e-mails on tuesday, wednesday and thursday
e. Average open rates is usually 45% for paying customers
f. Average open rates are usually 15% to 20% for prospects
g. Remove e-mails that didnt open e-mails for a long time