Fix outgoing email server issues

[kjporter]

Description
ZTL web services use Dreamhost for SMTP outbound mail service. We've found that this service has a very high spam rating and results in a lot of undelivered emails. This issue will implement solutions intended to increase delivered outbound mail by implementing appropriate countermeasures.

Acceptance Criteria

• Implement plain-text fallback in all email templates (text: in Mailable class)
• Dress-up html email templates with logo and filler and styles (see Tyler's note)
• Implement unsubscribe mechanism and add it to email footer
• Check DKIM config (wm-only)
• Add additional send from addresses

Accepted By:

Dev Notes

XD Notes

Working Branch

PR

Feature Toggle

QA Notes

Deployment Notes

[kjporter]

@c0repwn3r Please add your thoughts in here - looking for any suggestions you have to improve the reputation of our mailer

[coredoesdev]

I’ll make a writeup and drop it in here. Currently doing some more testing on individual sieve scripts to determine exactly what each flag is being triggered from.

[coredoesdev]

Biggest problems

• MailChannels has amassed a reputation for being very easy to hijack and refusing to implement basic security after being informed of the issues. They are very popular however, so are generally allowed through most mailservers, with an increased level of scrutiny
• DreamHost's mailserver reputation, along with most major hosting providers, is very bad
• We are sending html-only emails, which is both bad for a11y and will generally increase your spam score
• Despite being html-only, our emails are very short and are generally very CTA-y, which for providers that use heuristics will get us flagged. You actually want to add extra filler (e.g. logos, layouts, extra text), etc, as it makes your email more legitimate to heuristics
• We need an unsubscribe system. Even if our emails are important, people should be able to turn them off if they want, otherwise they'll just delete them all or flag them as spam which hurts our sender rep

Minor things

• I don't know if we have DKIM setup. If we don't, do that
• "Personality" can be a great way to add filler. E.g. add something unique to our emails - having generic "Dear XYZ this email is to inform you of blah blah" is more likely to get our emails dropped by heuristics.. adding logos/styles/interesting text will both make it more likely people actually read our emails and increase delivered %
• We send all of our emails from info@notams.ztlartcc.org - splitting this up into unique addresses and names would likely help