SendGrid vs ActionMailer vs mail server

Question

I am building a Rails application with the following functionality: when receiving emails from users, parse the content, perform some tasks and send update emails to users, with low latency.

For receiving emails, I have MailMan gem. For sending email, I have ActionMailer. For mail server, I am using Gmail with Pop3.

It seems that SendGrid is a popular thing for email. I have a hard time understanding what exactly SendGrid does beyond ActionMailer. Is SendGrid an SMTP email server and an alternative to my Gmail Pop3? Does it handle incoming emails?

What are the advantages over ActionMailer?

Answer 1

I work at SendGrid.

SendGrid is primarily for SMTP (outbound) email. You can read an overview explaining what SendGrid does here. The advantages of using SendGrid are better deliverability (less likely to go to spam folder), scalability, analytics, and access to APIs for doing more complex things like associating unique arguments with individual emails. We do have an Inbound Parse webhook that will help you parse inbound emails without the need for storing those messages in a mailbox. We do not offer any mailboxes (POP3/IMAP) or any message storage capabilities.

SendGrid and ActionMailer are complimentary. You can use SendGrid with ActionMailer as described in our docs.

You don't mention if you are using gmail as an SMTP server to send your app's messages, but if you do, there are some limitations such as the number of emails you can send per day.

Let me know if I can answer any more questions for you. Thanks!