EMAIL DELIVERY ERROR: the plugin WP Mail SMTP v2.4.0 logged this error during the last time it tried to send an email:

Mailer: Zoho Mail

Internal Error (500) - You need to verify the ReplyTo address to send emails using this account. Please verify the ReplyTo address.

Consider running an email test after fixing it.

How can I do this? The old forum article links do not work, as far as I can tell my replyto is also the sender address