My webshop emails are not arriving

This is the most expensive problem a webshop has: the customer pays, receives nothing, and then calls you.

First check what is failing

All confirmations, or only at certain providers? If one provider blocks, it is a reputation problem. If everything fails, it is a configuration problem.

The most common cause

The shop sends directly from the web server without authentication. Configure a real SMTP connection with credentials — that fix resolves most cases.

The sender address

It must be on your own domain. Sending with the customer's address as sender fails authentication every time.

Keep this mail separate

Order confirmations should not go through the same channel as your campaigns. A campaign that damages your reputation then takes your confirmations down with it.

Monitor it

An alert when the number of confirmations sent does not match the number of orders warns you before your customers do.