McAfee’s Email Gateway solution is in end of life and we need to find a suitable replacement option.
Do you think SendGrid or Mailjet would be a good replacement option considering that we are looking only for the SMTP relay functionality without compromising on the email safety?
For overall email, we have Microsoft Exchange Online Protection (EOP) which acts as a gateway for Office 365 Services.
I've worked with both. I liked SendGrid better, though it worked better with their API. For SMTP based mail relay we got much better results with Impactia (which we originally used for other stuff). if you can work with API - SendGrid would be easy to use.