If you recently configured your email account in Outlook, chances are the error is caused by a configuration mistake. Keep in mind that a misspelled mail server name or the wrong port setting will cause Outlook to show the “421 cannot connect to SMT/ SMTP server” error when sending or receiving an email.
- 1 How to fix 421 cannot connect to SMT?
- 2 How do I fix SMTP Error 421?
- 3 What is server error 421?
- 4 Could not connect to SMTP host port 25 response 421?
- 5 Can not connect to SMT?
- 6 What is the SMTP server port?
- 7 How do I fix an SMTP error with Outlook?
- 8 What is a 420 error?
- 9 How do I fix Error 521 Web server is down?
How to fix 421 cannot connect to SMT?
There is a chance that the 421 cannot connect to SMT error is caused by a configuration mistake. To fix it, you can try removing and re-adding your email account in Outlook so that the correct settings can be configured automatically.
How do I fix SMTP Error 421?
How to Fix Error 421 Cannot Connect to SMTP Server?
- Send/Receive Groups window.
- Changing port numbers in Internet Email Settings window.
- Enabling “Use the same settings as my incoming mail server” option.
- Recreating Outlook account.
- Turning Off Firewall in Windows Settings.
- PST selection window in Stellar Repair for Outlook.
What is server error 421?
The error message in the bounce mail would usually be ‘421 Too many concurrent SMTP connections; please try again later. The error message denotes that the connections to the recipient mail server have exceeded the limit. This high traffic can sometimes be a temporary problem due to a spike in the connections.
Could not connect to SMTP host port 25 response 421?
SMTP Response 421 can also be received as a result of your message server sending an email where the total number of TO, CC, and BCC users results in a number of simultaneous SMTP connections that is in excess of the number of connections your ISP or SMTP service allows.
Can not connect to SMT?
Outlook Configuration mistakes – The most common reason for the Outlook cannot connect to SMTP / SMT server error is a configuration mistake in Outlook settings. Interference caused by a VPN connection – Some VPN providers (particularly new products) might not have the email server that you used whitelisted.
What is the SMTP server port?
Port 25 is the original standard SMTP port. Today, the Internet Assigned Numbers Authority (IANA), the group responsible for maintaining the internet addressing scheme, still recognizes port 25 as the standard, default SMTP port. SMTP was designated to use port 25 in IETF Request For Comments (RFC) 821.
How do I fix an SMTP error with Outlook?
Fix SMTP Server error in Email
- Open your email client program (Outlook Express, Outlook, Eudora or Windows Mail)
- Click “Accounts” in the “Tools” menu.
- Click on your email account then click “Properties” button.
- Click “General” tab.
- Ensure that the “E-mail address” is your valid address for this account.
- Click “Servers” tab.
What is a 420 error?
420 Method Failure (Spring Framework) A deprecated response used by the Spring Framework when a method has failed. 420 Enhance Your Calm (Twitter) Returned by version 1 of the Twitter Search and Trends API when the client is being rate limited; versions 1.1 and later use the 429 Too Many Requests response code instead.
How do I fix Error 521 Web server is down?
Error 521 Solutions Make sure Cloudflare IP addresses aren’t blocked or throttled. In your origin web server’s firewall or other security software, allow all Cloudflare IP ranges. Confirm that you have installed a Cloudflare Origin Certificate if your SSL/TLS mode is Full or Full (Strict).