User registration emails not being sent

Hi all,

Can someone tell me how to solve the following?

WordPress 4.2.2 is installed in a subdomain (ie multi.domain.com)
When a user registers they receive the registration successful message — check your email.

An admin notification email is sent (I have verified mail is working on the server…etc.), but the confirmation email is not sent to the user.

My host allows for multiple email accounts so I have set one up as ‘wordpress@domain.com’ and verified it works for both sending and receiving.

I suspect the issue is that wp is trying to send email from ‘wordpress@multi.domain.com’ (note the ‘multi’ prefix) however, I cannot setup any emails using subdomains on my host.

Is there a setting I can change in wordpress to have the ’email from’ ‘not’ use the subdomain sitename?

Appreciate your help on this!!

Cheers,