[notreallyserio]

I'm not sure this is limited to SendGrid. Are there comparable email services that don't use shared IPs or that have done a consistently good job of stopping spammers? I've had moderate-to-poor luck with Mailgun (Yahoo and Microsoft don't really like them much).

[raxxorrax]

AWS SES doesn't seem to have a problem, but you have to describe your usage and verify the domain from which you will be sending.

They usually act within 24h to enable sending if you have set up everything.

[jwr]

Postmark is next on my list of services to try. They specifically say "It’s our job to provide you with great deliverability with or without dedicated IP addresses" and they allow you to separate transactional E-mails from the rest.