[ttul]

The even greater problem with sending email is that your platform will immediately and comprehensively be abused by spammers.

To make your email woes go away, I would recommend using MailChannels [1] rather than SES or SendGrid because MailChannels has a built-in anti-abuse layer that will send you a webhook whenever a bad user is detected. SES will just terminate your account, which probably isn't what you want. Also, at high volume, MailChannels costs less.

[1] Disclosure: MailChannels is my company.

[novaleaf]

not just emailing. any service that could theoretically be utilized by spammers/scammers will be. (Source: my own SaaS)