fixes https://github.com/TryGhost/Team/issues/2557
When a member doen't have a name, and the first_name replacement doesn't have a fallback, we did show %recipient.first_name% instead of an empty string.
fixes https://github.com/TryGhost/Team/issues/2522
When sending an email for multiple batches at the same time, we now
reuse the same email body for each batch in the same segment. This
reduces the amount of database queries and makes the sending more
reliable in case of database failures.
The cache is short lived. After sending the email it is automatically
garbage collected.
closes https://github.com/TryGhost/Team/issues/2388
We have seen examples of sites with member emails that have invalid characters that can cause an entire email send to fail, or just cause a failure to those addresses. The issue that allowed members with invalid email address to be saved was patched earlier, but its possible there are still sites that contain some of those invalid email addresses.
This change updates new sending service to filter out the recipients with invalid email address before passing them to mail provider, so these rogue addresses don't affect the whole batch in anyway. We also trim the recipient emails to clear out any spaces first, which is the most likely culprit.
- uses new email validator that detects invalid email addresses with special chars
