I tried every top email marketing tool

In the "you had one job" category of things to look at from an email marketing tool:

What about email deliverability?

Deliverability refers to the percentage of emails you send that actually make it into your contacts' inboxes.

The tool you choose can impact deliverability. However, it’s a complex topic, and I won’t dive into the details here. If this is something you’re concerned about, there are experts far more knowledgeable than me who can explain it thoroughly.

This ought to be disclaimed at the top instead of the end.

I disagree. It’s a dimension of the decision, certainly not the “one thing” to look for.

… unless you’re a spammer haha.

Or unless your emails matter to your customers, with you seeing them as individual names instead of spray and pray marketing.

Deliverability is the single most important thing to reach individuals in the first place, even more critical to maintain the transactional or workflow email relationship.

Anthropic right now has an issue where their "passwordless" emails go to junk for M365 customers (85% of SMBs in U.S.), people literally can't use the service since the email isn't delivered to the inbox.

To your point, in a past gig helping thousands of businesses with turning contacts into not just buyers but fans, I discovered mass marketers don't really care about deliverability at the level of "every single communication must land with every person".

At the same time, I learned customers you want to build a relationship with very much do care. Ever since, when evaluating these, I start there, even before price. How many communications, transactions, or workflows with a future buyer with intent are you willing to fail to connect?

"You had one job" means the primary, not only, dimension. Yes, the primary job of a mailer is for the mail to get there.

I agree there's lots more to look for as well!

That ("Anthropic's" deliverability issue) is a Microsoft issue. Don't normalize Microsoft's bad practices.

That's just one current example of when email delivery matters, likely to resonate with HN as being senders and receivers they recognize struggling with this. Not just a Microsoft thing, we can talk about a dozen where Gmail files things wrongly as well, and where the common element is the mailer.

These mailers all have different levels of trust and deliverability stats. It's critical to know.

I don't think you're getting what I'm saying here. If an email provider is throwing away wanted messages from legitimate senders because of some "trust" metric, then it is that email provider's reponsibility, not the sender's, to make damned sure that doesn't cause the loss of desired email.

You are of course correct that neither GMail nor Microsoft 365 or Hotmail or whatever they call it this week is suitable for any serious use.