Can send email via alias but not main email address

Can send email via alias but not main email address

Hi guys, hope somebody can help me with this!

I've just joined Zoho Mail, and am having trouble with this new account. My business (djsoundandlight.co.uk) has two email addresses, info@ and sales@. I've set up an account with Zoho as info@, and have added sales@ as an alias, so that I have the same inbox for both email addresses. I'm receiving emails from both addresses no problem, but can only send via the sales@ alias. If I send something via info@, it appears to go through fine at this end, but never appears at the recipient's end. What am I doing wrong?