I’m using Mighty Mass Mail and I’m finsing several problems:
I use it to send newsletters with an article a day in a Membership section-category
1) Sometimes the link in the email which is received by destination user leads to a totally unconfigured page. Visually, link is the same as usual. But, when clicking on it, it produces a different code, so it brings to a bad page.
2) It’s not possible to program a sending for a given hour. Well: you can program it, but many hours later of the scheduled sending time, and even one day after, it is not sent. You need to send it manually.