Email issue after changing settings

[dirntknow]

Sorry for not being able to explain this too well but after following a FAQ https://www.zen-cart.com/tutorials/index.php?article=73, at step 3 it recommends to change to smtpauth. I couldn't gett his to work but after switching back to php I find that an email sent to a dummy customer i created, it ends up coming back to me in my store folder in outlook. Its not bouncing back, its like i've sent it to myself. Another email sent to a dummy customer I created using a yahoo account appears to be sent but disappears completely! I've installed zencart on another domain i have and that is ok but the settings all appear to be the same!!
What have I done??!!!

[MattZCM]

Did you also enter your SMTP credentials further down the 'Email Options' page (before switching back to PHP)?

[dirntknow]

I did enter the smtp info but found it wouldn't mail to my dummy yahoo account at all. When i switched back to php it was still the same. I'd backed everything up so reinstalled it all including the database but still the same. I can probably bypass the issue by mailing thru my mail program instead of the admin back-end but it'd be nice if it worked correctly. I'm now thinking i'd not actually mailed thru the admin anyway so may have always been a problem?