Re: Easiest/best way to create an email using local MS Outlook with file attachments?

A better option than Outlook (ugh!): Check out SendGrid (now part of Twilio).

SendGrid, MailJet et al are definitely the way to go for bulk emailing, however are possibly overkill for sending occasional one-off messages from an application, which is what I took the requirement to be.

"I'm already paying for Office 365, why am I paying for SendGrid on top to send a few emails?"