Can't Send Email? Settings, Limits and Fixes

If messages are stuck in your outbox or bounce back, the cause is almost always one of four things: wrong server settings, a sending limit, DNS pointing elsewhere, or a mailbox that has been paused for security. Work through the checks below.

1. Check your mail client settings

Whether you use Outlook, Apple Mail, Thunderbird or the Gmail app, the settings are the same:

Re-type the password carefully. If you recently changed it in StackCP, every device and app using the mailbox needs the new one.

2. Check you are within the sending limits

To protect the platform from spam, these limits currently apply:

• Mail sent by your website (PHP mail from the web server): 500 emails per day
• Mail sent from a mailbox: 8,000 emails per day
• Attachments in webmail: up to 32 MB
• Total message size across the network: up to 50 MB

Once a limit is reached, further mail from that account or package is held back. Limits can change; ask support if you need more. For newsletters, use a dedicated email marketing service instead of your mailbox.

3. Check your MX records

If your mail is hosted with FimuroHost, your domain's MX record should point to mx.stackmail.com. Check it with a free tool such as MXToolbox or from a terminal:

nslookup -type=MX yourdomain.com
dig MX yourdomain.com +short

                        
                    

If you see a different mail server, your email is being handled somewhere else, or your domain is not using our nameservers.

4. Was your mailbox disabled?

If you get an error mentioning suspicious activity, sending from the mailbox has been paused, usually because the password was guessed or leaked and the account started sending spam. Open a ticket so we can check and re-enable it, and set a new strong password straight away.

Other things to try

• Send a test from webmail. If webmail works but your app does not, the problem is in the app's settings.
• Remove and re-add the account in the mail app; old saved settings can linger.
• On some networks port 587 or 465 is blocked. Try the other port, or test on mobile data.

When you contact us, please use a support ticket rather than chat so we can attach logs and bounce messages.

Need help?

If anything here does not work as described, our team is happy to take a look. Open a support ticket from your FimuroHost client area or message us on WhatsApp at 01818160926.