What a hard bounce is
A hard bounce is a permanent rejection by the recipient's mail server. Common causes:
The mailbox hadn't been created yet when the email was sent.
The address contains a typo.
The mailbox was deleted, e.g., after someone left the company.
The domain doesn't accept emails.
After that, the address ends up on a blocklist. This protects the deliverability of all simpleclub emails. Anyone who keeps sending to unreachable addresses is flagged as spam by email providers more quickly.
Sending again doesn't help as long as the block is in place. That's true even if the mailbox is active by now.
Case 1: The address is wrong
Correct it in the Admin Panel:
Go to "Users".
Open the affected user.
Correct the email address and save.
Resend the verification email.
The corrected address isn't on the blocklist. Sending works right away.
Case 2: The address is correct
This typically happens with new mailboxes: you created the users before IT activated the addresses. The address is correct, but it wasn't reachable when the email was sent.
You can't lift this block in the Admin Panel. Saving the address again doesn't reset it either. Contact support and send us:
the affected email addresses as a list
the name of your company
We'll lift the block and trigger the invitations again. You'll hear back from us as soon as the emails have been sent.
How to avoid hard bounces
Only invite users once their mailboxes are active. For new employees, it's worth checking quickly with IT.
Check addresses for typos before a larger import.
Deactivate users who have left the company.