Wondering why you see SMTP response 421? Do you know How To Fix Outlook 421 Cannot Connect To SMTP Server Error?
Does sending’ reported error (0x800ccc67) ’ the server responded 421 cannot connect to SMTP server irritate you?
Then hey! Don’t you panic as we’ve got you covered!
In this blog, we are going to talk about the causes behind outlook error code 421. Moreover, we will also guide you on How To Fix Outlook 421 Cannot Connect To SMTP Server Error.
Firstly, what is Outlook Error Code 421?
Table of Contents
- 1 Firstly, what is Outlook Error Code 421?
- 2 WHAT CAUSES SMTP RESPONSE 421?
- 3 How To Fix Outlook 421 Cannot Connect To SMTP Server Error?
- 4 STELLAR OUTLOOK PST RECOVERY SOFTWARE: THE ULTIMATE SOLUTION
Outlook error 421 precisely, is a common SMTP error that is likely to occur when you try to send an email in Outlook. Additionally, it occurs as a result of:
- Antivirus program on your PC intervening in Outlook
- Besides, it occurs with IMAP Outlook accounts with faulty SMTP configurations
Secondly, what causes SMTP error 421 connection to server failed?
Let us see below to know the causes of could not connect to SMTP host response: 421
WHAT CAUSES SMTP RESPONSE 421?
Before moving on to How To Fix Outlook 421 Cannot Connect To SMTP Server Error, firstly, let’s know its cause.
- Faulty Outlook Configurations: It is the main cause for SMTP error (421) connection to server failed in your system. Nonetheless, new or recent email configurations lead to this issue.
- Automated blocked traffic to block users from spam networks, from port 25 &26
- 3rd party firewalls block connections to some IP ranges
- Virus interference
- Corrupted PST files
Now that we know the causes, let’s find out How To Fix Outlook 421 Cannot Connect To SMTP Server Error?
How To Fix Outlook 421 Cannot Connect To SMTP Server Error?
Now that we know what leads to SMTP error (421) connection to server failed, we will now see How To Fix Outlook 421 Cannot Connect To SMTP Server Error.
Step 1: Reconfigure SMTP Settings
This gets counted as one of the most common reasons behind SMTP error 421 connection to server failed. It is certainly caused due to improper SMTP configuration. Thus, by reconfiguring it you will get to know How To Fix Outlook 421 Cannot Connect To SMTP Server Error.
Step 2: Disabling Your VPN, For A While
Evidently, VPNs are installed to keep your locations under wraps, hence providing access to geo-blocked web services.
However, these VPNs at times can act as a barrier. Ultimately, it can become a cause for outlook cannot connect to your outgoing (SMTP) e-mail server. It mainly intervenes in your browsing behavior that includes your access and transmission of emails in Outlook.
Therefore, you might wanna disable your VPN for a couple of seconds and thereafter try sending out the emails.
Step 3: Check Antivirus or Firewall
Undoubtedly, both these security software safeguard your system from malicious resources.
However, sometimes 3rd party firewalls antivirus forbids some IP ranges, including email servers.
Therefore, disable both these suites for a while if you don’t want to see outlook error code 421.
However, this will not be the case if your system has an inbuilt Windows firewall.
Step 4: Remove and Thereafter Re-add your Email Account
Yes, easy as a cakewalk! All you need to do is remove your email account and add it again to fix SMTP response 421.
Moreover, don’t forget to choose the Auto Account Setup instead of the Manual Setup option.
Step5: Try Changing SMTP Port Number
If you’re still clueless over How To Fix Outlook Error Code 421, try this.
Nonetheless, faulty SMTP configuration can also cause SMTP response 421. Hence, you might wanna change the SMTP port to fix the issue.
STELLAR OUTLOOK PST RECOVERY SOFTWARE: THE ULTIMATE SOLUTION
Inbuilt with high power and enhanced algorithm skills, Stellar Outlook PST Recovery Software is an incredible program that brings back all your important but lost mailbox data.
Nonetheless, it can repair severely corrupted PST files conveniently. Apart from this, Stellar can also restore lost data of large PST, without any hitch.
Furthermore, here are some of the excellent features of Stellar Outlook PST Recovery Software
- Easiest recovery of Outlook PST; moreover quite quick
- Backup of deleted of your Outlook data
- Preview of the recoverable data
This blog is a perfect example of a hit and trial method on how to fix Outlook SMTP Error. If one method doesn’t solve the error, try another, and another, and so on.
We hope this blog helped you understand How To Fix Outlook SMTP Error.
Now, go ahead! Send emails in Outlook by switching off all your worries about losing them!