I'm having issues with email delivery from the Userforms module, which hopefully someone can help me with.

My client has provided their own web hosting, with their email being handled by Office365. The MX records on their web hosting have been updated accordingly. However, emails from Userforms are not coming through. Their web host is saying that the website needs to send via Office365 (can Userforms even do this?)

Is there a workaround to get Userforms to use Office365 to process email? I had thought that, even though the MX records have been set, we could still send emails (but replies would obviously be routed to Office365).

Any help gratefully received. Thanks

MX records have nothing to do with _sending_ emails, they simply direct them where to go when they come /in/.

Office365 is denying the emails as they're (probably) configured to send from the same domain as the website.
Office 365 controls this email. Office365 knows it did not send these emails. Office365 then rejects them. As will any other email client bothered to validate the sender.

I believe it's simply adding (or modifying) an SPF record on your domain.
Look at your website's mail error log, it will list the bounces. With a proper error you can google the fix easily if the above is not the answer.

Many thanks for your reply.
So, am I correct in thinking that the whole "Office365" thing is irrelevant? (Of course, any reply to an emails would go to Office365, but that's fine)

No. It is relevant.

I was just trying to clarify your understanding of email, but it looks like I've confused you more. Read the link I supplied and hopefully that will be your answer.

Thank you for your clarification. I'm very grateful for your patience with me :)

So, do the SPF records need to be updated on the web hosting, or on Office365? The hosting company is saying that because they have no email accounts configured on their server, the userforms should be configured to use the remote mail server. Adding an email account to the hosting doesn't seem to make any difference.

To anyone still having this problem, you can use an SMTP Mailer module to send via Office365 quite easily instead of using the built in PHP mailer.

I'd set up the necessary DNS for this (single SPF record allowing mail from our IP) and Office 365 just wouldn't accept email from the PHP mailer. Looks like Office 365 won't take email that's made to look like it comes from the domain set up in their MX record.