Email is an ephemeral medium. A scientific journal be published twice a year, for an email newsletter, this will usually be disastrous.
Not only do you risk that your subscribers forget about you (and turn to the competition), if your newsletter is sent very infrequently — less often than at least once per month — it also stands a big chance of being perceived at spam.

The result may be lots of puzzled faces, unsubscriptions and complaints to your ISP calling you a spammer — all that in spite of your subscribers (actually) demanding and liking your content.

Send Newsletters at Least Once a Month

That's why you should

• send newsletters at least once a month to prevent
• bulk unsubscriptions and
• being perceived as a spammer.