While trying to send an email in Gmail, most of the users have reported facing Gmail server error 421. An error message usually appears on the system showing “server responded: 421 connect to SMT / SMTP server”. Mainly, the 421 error occurs when you are trying to use File Transfer Protocol or FTP to connect to the server. The error states 421 that too many connections are associated from one IP address. It basically indicates that there are too many connections or active connection or maybe even idle connections that are connected to the server through FTP, and it is preventing you from connecting with another connection or server. The error mainly occurs if the Gmail accounts are configured in Outlook.
So, if you want to experience an error-free emailing with Gmail, then you need to fix the issue with the minimum possible time. Hence, go through the article and solve error 421 without any trouble.
Reasons Behind the 421 cannot Connect to SMTP Server Gmail
421 cannot connect to SMTP server Gmail errors encountered in Gmail, when configured in the Outlook, can be broadly split into four different categories. These are:
- Outlook misconfiguration.
- Firewall-related issue.
- Filtered traffic on port 25.
- Interference caused by a VPN connection.
Moreover, besides the above four main causes, improper installation or outdated version of Outlook is also responsible for the error code. Hence, you need to choose the proper solutions depending on the reasons for the error code 421. You are not aware of the exact reasons behind the error message, then try all the solutions that are mentioned in the section below.
Different Methods to Eliminate Gmail Server Error 421
Here, in this section, we have provided some of the easy and effective fixes which help you to recover your Gmail from the Gmail Server error 421. Check them and implement them as mentioned.
Method 1: Resolve the Outlook Configuration Problem
It is possible that the error code appears if you recently configured the email account in Outlook. If there is any misspelt term in the mail server or any wrong port settings. If you manually configure your email account settings, then you can try re-adding your email account and add the correct settings. Follow this quick guide to add correct configuration automatically and solve the problem.
Before letting the Outlook reconfigure the settings option, first, you need to remove your email account. To perform the action, navigate to the File option and then from there move to the Account Settings. Select the Remove option.
After removing the account, press the New button. Then, select the Email account and then insert your details again. After that, press the Next and then, wait for the settings to be configured.
You need to send an email. If the text email successfully sent, your email account configured properly. While sending the email, if you get the same message, then follow the next method.
Method 2: Change the SMTP Port Number
Sometimes, the issue happens because of the Small Mail Transfer Protocol (SMTP) port is being filtered by the Internet Service Provider (ISP). It is known that some ISPs block traffic in Port 25 reduces the extent of automated spam. If that is the reason behind the Gmail server error 421, then you need to change the port number from 25 to 465.
To do this, at first, open the File option and then move to the Account Settings option. After that, choose the email account which consists of the error message and press the Change option.
After that, from the Change Account option, open the More Settings tab and select the Advanced wizard. Next, in the box near the Outgoing server, ensure that the type of encrypted connection is set to Secure Socket Layer (SSL). After completing the methods, try to send an email to check whether the error still persists or not. Otherwise, try the next one.
Method 3: Check for Firewall Interference
To protect your device from malicious attack and hack, the firewall is used for extra security barrier. But, sometime this third-party firewall blocks some IP address. The email server IP might include on the block list and as a result, the error code 421 appears on the system screen. To fix the error code you need to turn off the third-party software. To do that, launch the third-party software and go to the Settings option. From there you can disable the software for the time being.
Method 4: Check the Virtual Private Network (VPN) Interference
To secure the web traffic and stay anonymous while web browsing you might use a VPN solution. Sometimes, a VPN connection might prevent Outlook form communicating from the email server. In order to fix the issue, you should check the VPN interference. You need to disable the VPN network and check the status of the error code.
Method 5: Uninstall and Reinstall the Microsoft Outlook
If Gmail server error code 421 is occurring because of a corrupted or improper installation Outlook, then make a clear reinstallation and solve the error code. To perform the action, check out the steps that are mentioned below.
- At first, open the Control Panel option and then move to the Programs and Features option. After that, search for the Microsoft Outlook from the Name tab.
- Select the Outlook and right-click on it. A drop-down menu will appear, select the Uninstall option.
- After that, follow the on-screen instructions and uninstall the program.
- Then, open the manufacturing website and download the latest version of Microsoft Outlook. After that, install it on your device and restart the system. This will surely help you to resolve the issue.
We presume that this content might have been able to tell you which methods you should consider in order to fix Gmail server error 421. Apply the procedures as it is and checks which methods are the best suited for you. Do not forget to give feedback about the article and if you want more technical posts like this post about it in the comment box below.