Been using Amazon SES for years. I would like to know besides Amazon being cheaper, are there any advantages of going with Mailgun or sendgrid and having a dedicated IP. Which has the better deliverability rate?
If you're sending highly effective emails with a low spam rate and high open and click rates, it's better to use dedicated IPs. All of these ESPs support dedicated IPs, including Amazon.
For grouping, my suggestion is:
Postmark and Mailgun are ideal for highly engaging emails, excelling in both transactional and marketing emails.
Sendgrid and Sparkpost are suitable for moderately effective sending.
Amazon is recommended for medium-sized senders focused on sending marketing emails.
