What are best practices for using/selecting an ESP if you were to use a project like this and want to ensure reasonable deliverability?
PS: Postal SMTP is awesome.
starting to sound hopelessly naive
you deliver email updates to fund LPs that aren't unilaterally marking you as spam for no reason
This sounds hopelessly naive to me. If the receiver marks it as spam, it's spam. By definition. Work harder to only send emails to people who want them.
but that shouldn't effect the deliverability to everyone else, but thats a reality which has its own problem and has its own countermeasures.
when people asked OP if they had a solution to this, they hand waived it away. all closed sourced mailing list clients have solutions for this.
but anyway since somehow it is 2019 and people want to act like its 2009 on this matter I'll just skip ahead to echo the productive answer someone else left:
this could probably be run through Amazon SES with their DKIM settings
Spam is unsolicited commercial email.
if I sign up on a site, click the 'yes email me' button, and then mark the email as spam when I get it, I am the one acting incorrectly, not the sender who is literally doing what I instructed them to do..
Unsubscribing from email lists can be cumbersome and non-uniform, which is usually why people just hit that spam button instead. It always provides them a uniform interface and largely achieves the same goal from their perspective.
People forget subscribing and hit "Spam", which has an impact on the sender reputation and affects future deliverability for that sender.
One of the factors I didn't mention in previous comment is presence of physical mail address.
Not sure what "unfortunately for me" is in reference to - BigMailer isn't a platform for cold emails (there are plenty others that specialize in cold email campaigns) and Amazon SES doesn't give a free pass on the practice either.
Using an ESP will generally simplify the amount of work necessary to achieve good delivery, but due to the complexities of domain reputation and fingerprinting, very occasionally they can also be the cause of delivery problems.
General guidelines:
- It's a bit harder to predict how deliverability will turn out at smaller ESPs, vs. well-established ones like Sendgrid, SES, Mailgun, and perhaps Mailchimp.
- DKIM, SPF, DMARC (p=none is fine to start; gmail has a guide for deploying dmarc https://support.google.com/a/answer/2466563)
- Use the same root domain everywhere within your email: From, Return-Path, DKIM signature headers; URLs for links and images in the message body. (Separate subdomains are fine, e.g., img.example.com, bounce.example.com)
- Having your sending domain show up in third party email can cause problems. Try to avoid it if possible; use a separate domain as a last resort.
- Send consistently. Some variation in sending patterns will be tolerated, but you'll probably have trouble if you send 500 messages a day most of the time, then once a month you send 100,000 messages.
- Consider a dedicated IP if you're sending over 50,000-ish messages a month.
- You may want to split up transactional email from marketing, sending these from separate IPs and/or subdomains.
- Finally, make sure you're sending email your recipients find valuable and are interested in receiving. Too much disinterest/disengagement can cause delivery issues.
I would recommend to NOT send different email types from different providers, like use SendGrid or SES for transactional emails and then some other platform for marketing emails, especially using the same sender domain. That's because email header signature and tracking links will be different and email box providers like Gmail can find it suspicious and send emails to Spam. And then there is the issue of processing and syncing bounces/unsubscribes/complaints data.
Keeping all email campaign types in a single platform allows for centralized processing of bounces/unsubscribes/complaints date and protects future campaign engagement + sender reputation.
That said, you may be surprised by the number of large organizations that have a dozen or more services that send mail on their behalf, for various different purposes... it's not optimal, from a deliverability perspective, but it's also not usually going to cause deliverability issues by itself as long as everything else is in order.
Just saw an email from Starbucks in the spam folder - all because of a few words that no doubt triggered the spam filter.
Also, the quality and size of the starting list matters too because a large list (like the OPs) or unengaged list can have a high bounce and low engagement rate, which factors into future deliverability.
Now before you mention how this should be a solveable problem inn AWS, we’re already well underway testing with the client. The problem presented itself as a manifestation of inheriting the last guy’s infrastructure and working to...unfuck a lot of his questionable design choices.