Is it a reasonable expectation that my inbox-rate will increase if I will transition from self-managed (Postfix) to a service like SendGrid or Amazon SES?
If have an email list of 100k+ that receives application notifications; I had reputation/blacklist issues in the past so am wondering if the higher reputation of the above providers should help me with increasing my inbox rate while I also ramp up the quality of the emails
Yes. This is a big part of what paid email providers do. But keep in mind they also monitor quality and have limits initially -- if you sign up and then send out to 100k there might be a problem, and you might have to request a limit increase before you do it.
Last time I requested a SES increase, they bumped it to 50k although I didn't even ask for that much.
Hello,
There are lots of thing causes descreasing inbox rate.
I prefer to use Amazon SES. They do everything you want. You only should warm up ip adress and have a good reputated domain.
For mor details, you can visit our blog to see details: https://popupsmart.com/blog/why-emails-go-to-spam-instead-of-inbox/