421 Cannot Connect To SMTP Server: Cost Effective Support to Resolve Outlook Error

Outlook is one of the best web-based suites of webmail and is gaining popularity as a top notched email application. Windows users extensively manage it for sending and receiving emails. However, its fast communication does not make it glitch free. The error mostly reported by users is Outlook Error 421. Thus, the Professionals at Microsoft Support unit are working throughout the day to fix the issues faced by their clients. 

This common SMTP (Simple Mail Transfer Protocol) Outlook error message appears when you are trying to send an email in Outlook. But the panic days are over as this article provides you with a vivid insight about the 421 Cannot Connect To Smtp Server issue.

Probable Causes Behind 421 Cannot Connect To SMTP Server?

The 421 error in Outlook generally occurs due to many countless reasons. The underlying causes can be broadly categorized into these categories: 1. User-related issues 2. issue with the ISP  3. Server-side matters.

Following are the causes related to the issue, have a look:

• Firewalls settings or any anti-virus software might be blocking the connection to specific IP ranges.
• Due to wrong configuration settings of Outlook or newly configured email accounts, the issue can suddenly arise.
• If you misspell the mail server name and enter it in the wrong port setting in Outlook, then 421 Cannot Connect To Smtp Server issue occurs.
• Some ISPs are associated with blocking the traffic through port 25 to reduce spam, which in turn affect the connectivity and result in outlook 421 error.
• Certain server firewalls based on undefined anomalous behaviour blocks specific IP ranges and restricts the actual function of Outlook.
• If you exceed the attempts for the login, then it can lead to blocking of the IP address which will subsequently lead to outlook 421 error.

Fix Outlook Error 421 Cannot Connect To SMTP Server Issue?

Follow the step-by-step debugging process to fix the 421 Cannot Connect To Smtp Server issue.

Solution 1: Fix Client End Issues

You need to check if you can successfully connect to mail server IP, then the issue must have relation with the Outlook setting. You need to configure the Outlook mail client to its default setting. Check and insert the correct the port number as well as the SSL settings for the mail servers you usually use.

Solution 2: Verify Network Issues

To reverse ISP port blocks and to allow you to send emails, you need to configure SMTP on a different port in separate servers. You can use a non-standard port to secure your email server. Once the mail server gets the exact configuration, add this port to the firewall list, to permit incoming connections to that port.

Solution 2: Secure with PST file

If you notice that the underlying cause of the error is corrupted in the PST files, then it will block you out of your email account. Moreover, you will be at risk of losing all the critical data from your mail account.

The best way to resolve the error is to ensure that you can make a full data recovery. You need to download a reliable PST repair tool to recover your data as well as repair the corrupted files.

Are you still searching for solutions to fix the issue? Then your system might be in urgent need to help. You can ask for remote assistance or doorstep service from recommendable tech support.

For Additional Tech Support Connect With Experts 24×7

You can choose among the multiple platforms to connect with the diligent technicians if the above solutions fail to work. You get the assurance of prompt help with instant troubleshooting hacks.

Chat with the experts and avail professional help than never before. Interact to obtain expert opinion through the live chat portal.

Mail your queries regarding 421 Cannot Connect To Smtp Server error to eradicate the issue. You can avail our services at an affordable rate by dialling at Outlook Support Number +1-855-334-7340. Don’t delay, reach us now!