Mail Bouncing from MS Exchange- 421 4.4.2 Connection dropped due to SocketError'

Question

Mail Bouncing from MS Exchange- 421 4.4.2 Connection dropped due to SocketError'

Manjula Wijeyaratne 45

Hello,

This problem is now about 3 weeks with no solution in sight.

When we email to 3 or more Gmail accounts, (with or without other domains/email addresses & with/without attachments), we find the all the Gmail accounts bouncing with the above (subject line) error message. The other recipients receive their mails.

When we send mail up to 2 Gmail accounts, (with or without other domains/email addresses), the Gmail accounts receive their mail.

For example ; 1) [@gmail.com]; 2) [@gmail.com]; 3) three @gmail.com; [@xyz.com]; [@lhr.com] are in the recipient list, the Gmail addresses will bounces and [******@abc.com] will go through. All of these concerns are with same addresses we have been communicating with for years, with no problems prior.

Our service provider is Office365 / MS Exchange. If we use the Outlook web-app (on Chrome) or MS Outlook client app, it is the same, so it is not my settings nor the application. The way we see it, problem seems to be with MS Exchange and not my end.

ADDITIONAL INFO - our mail address in concern is [******@dandwassociates.com] & ******@dandwassociates.com

error code - Generating server: SEYPR06MB5087.apcprd06.prod.outlook.com Receiving server: SEYPR06MB5087.apcprd06.prod.outlook.com Total retry attempts: 14 example .......@gmail.com . 9/12/2023 10:39:23 AM - Server at SEYPR06MB5087.apcprd06.prod.outlook.com returned '550 5.4.300 Message expired -> 421 4.4.2 Connection dropped due to SocketError' 9/12/2023 10:38:18 AM - Server at gmail-smtp-in.l.google.com (2a00:1450:4025:401::1a) returned '421 4.4.2 Connection dropped due to SocketError'

NEW INFO

_*Our email to only 2 gmail addresses bounced as well.
The mail was sent Outlook on Chrome browser.

Please do help us urgently.

Thank you

Manjula*_

Kesniel Acton 5 Reputation points

2023-09-15T13:14:40.5166667+00:00

I have seen this happen with two different Office 365 accounts. Bounces everything to gmail. Can confirm a single address is not bounced.
Jim Hancock 0 Reputation points

2023-09-19T04:22:10.6033333+00:00

I am having the exact same problem as Manjula Wijeyaratne in the previous post. I'm using the same email distribution list I've been using for years and several emails I have done since September 16th have had the same results in getting bounce back of the Gmail email addresses. All other addresses work fine. Something must have happened during the month of September 2023. It is very frustrating. Now I have to send individual emails to each Gmail account otherwise they won't receive my email.
Manjula Wijeyaratne 45 Reputation points

2023-09-19T04:44:14.1766667+00:00

Hi Guys,
From the Admin page of the Office 365 account, I clicked on the Help & Support and raised a "ticket". A "Support Ambassador" called (within an hour) and went through the process.
At the moment, it looks like resolved :).

Having said that, there were 3 calls from MS. The first 2 thought it was resolve, but, No. The 3rd person (on day 3 & ticket #3), took about 30 to 40 minutes with us, and (fingers crossed) resolved. There was a time that he took a minimum of 10 minutes on behind the scenes work he did.

What he looked for on our system ?
From the admin account, he accesses Exchange. From there he looked at the email addressed that bounced, got reports for those that bounced and then put me on hold for 10 minutes or so.

Hope this helps.
I can't help you guys beyond that as I'm not tech-savvy beyond this :(.
Cheers
Jim Hancock 0 Reputation points

2023-09-19T21:11:56.49+00:00

Thanks Manjula. This certainly looks promising. I'll try a sample email tomorrow to see if the problem has been resolved. I sure hope so. This has become most frustrating for a lot of us!!

Jim
Jamie Rosenblatt 5 Reputation points

2023-09-20T18:50:52.36+00:00

Having the exact same issue. I was sent to gmail to get off their blacklist. I submitted but now it takes 2 weeks to get a response.
Angelo Papiccio 0 Reputation points

2023-09-24T23:49:41.4+00:00

I too am having the exact same issue. Is the problem MS end or Gmail end?

I will raise a support ticket on both I guess to be sure. How did you raise a Google ticket @Jamie Rosenblatt ? I keep getting directed to Google One for their premium service. I do not have an account with them, just a consumer Gmail address.
Jamie Rosenblatt 5 Reputation points

2023-09-25T01:38:57.6+00:00

They are aware of the problem, and getting a lot of people with support tickets. I was told they are going to have it fixed ASAP, so don't think the blacklist thing I did is going to matter. This is currently on the admin portal right now: Exchange Online: Reminder to authenticate outbound email with SPF, DKIM, and DMARC See Details. I click on see details and stiff don't know how to do this, so hopefully they are fixing it, but I still have my ticket open. @Angelo Papiccio

6 answers

Your answer

Kesniel Acton 5 Reputation points

2023-09-15T13:14:40.5166667+00:00

I have seen this happen with two different Office 365 accounts. Bounces everything to gmail. Can confirm a single address is not bounced.
Jim Hancock 0 Reputation points

2023-09-19T04:22:10.6033333+00:00

I am having the exact same problem as Manjula Wijeyaratne in the previous post. I'm using the same email distribution list I've been using for years and several emails I have done since September 16th have had the same results in getting bounce back of the Gmail email addresses. All other addresses work fine. Something must have happened during the month of September 2023. It is very frustrating. Now I have to send individual emails to each Gmail account otherwise they won't receive my email.
Manjula Wijeyaratne 45 Reputation points

2023-09-19T04:44:14.1766667+00:00

Hi Guys,
From the Admin page of the Office 365 account, I clicked on the Help & Support and raised a "ticket". A "Support Ambassador" called (within an hour) and went through the process.
At the moment, it looks like resolved :).

Having said that, there were 3 calls from MS. The first 2 thought it was resolve, but, No. The 3rd person (on day 3 & ticket #3), took about 30 to 40 minutes with us, and (fingers crossed) resolved. There was a time that he took a minimum of 10 minutes on behind the scenes work he did.

What he looked for on our system ?
From the admin account, he accesses Exchange. From there he looked at the email addressed that bounced, got reports for those that bounced and then put me on hold for 10 minutes or so.

Hope this helps.
I can't help you guys beyond that as I'm not tech-savvy beyond this :(.
Cheers
Jim Hancock 0 Reputation points

2023-09-19T21:11:56.49+00:00

Thanks Manjula. This certainly looks promising. I'll try a sample email tomorrow to see if the problem has been resolved. I sure hope so. This has become most frustrating for a lot of us!!

Jim
Jamie Rosenblatt 5 Reputation points

2023-09-20T18:50:52.36+00:00

Having the exact same issue. I was sent to gmail to get off their blacklist. I submitted but now it takes 2 weeks to get a response.
Angelo Papiccio 0 Reputation points

2023-09-24T23:49:41.4+00:00

I too am having the exact same issue. Is the problem MS end or Gmail end?

I will raise a support ticket on both I guess to be sure. How did you raise a Google ticket @Jamie Rosenblatt ? I keep getting directed to Google One for their premium service. I do not have an account with them, just a consumer Gmail address.
Jamie Rosenblatt 5 Reputation points

2023-09-25T01:38:57.6+00:00

They are aware of the problem, and getting a lot of people with support tickets. I was told they are going to have it fixed ASAP, so don't think the blacklist thing I did is going to matter. This is currently on the admin portal right now: Exchange Online: Reminder to authenticate outbound email with SPF, DKIM, and DMARC See Details. I click on see details and stiff don't know how to do this, so hopefully they are fixing it, but I still have my ticket open. @Angelo Papiccio

Answer 1

Manjula Wijeyaratne 45

Hello,
Further my comment of 19 Sept, the problem did not get resolved. So, we kept chasing and "tickets".
Today, the "Senior Engineer" who spoke to me, resolved it.

He looked at the DKIM settings on the O365 security settings. In it, there is an "enable/disable" switch. Ours was off and we couldn't switch it to Enable. However it gave a text box.
The MS engineer got us to copy the text, and we had to visit our Domain host (Go Daddy for us). And, in their DNS Management / DNS Records settings, under Cname settings, we had to enter some new components twice.
Your support engineer will take you through this.

Hope this helps you.

Cheers,

Rick Watts 0 Reputation points

2023-10-05T10:59:27.5066667+00:00

@Manjula Wijeyaratne thank you, that indeed resolved my issue for three domains hosted on GoDaddy. It took two tries to get the exact settings and verbiage, I sent the current settings off to the MS Tech on my service ticket and he sent back recommended changes. Added additional CName records and correct DKIM settings. I have removed the MX connector and turned TLS back on and everything is now working fine. No bounced emails to Gmail.

Answer 2

Manjula Wijeyaratne 45

Hi,
From the Admin page of the Office 365 account, I clicked on the Help & Support and raised a "ticket". A "Support Ambassador" called (within an hour) and went through the process.
At the moment, it looks like resolved :).

Having said that, there were 3 calls from MS. The first 2 thought it was resolve, but, No. The 3rd person (on day 3 & ticket #3), took about 30 to 40 minutes with us, and (fingers crossed) resolved. There was a time that he took a minimum of 10 minutes on behind the scenes work he did.

What he looked for on our system ?
From the admin account, he accesses Exchange. From there he looked at the email addressed that bounced, got reports for those that bounced and then put me on hold for 10 minutes or so.

Hope this helps.
I can't help you guys beyond that as I'm not tech-savvy beyond this :(.
Cheers

Manjula Wijeyaratne 45 Reputation points

2023-10-05T06:42:18.8933333+00:00

Hello,
Further my comment of 19 Sept, the problem did not get resolved. So, we kept chasing and "tickets".
Today, the "Senior Engineer" who spoke to me, resolved it.

He looked at the DKIM settings on the O365 security settings. In it, there is an "enable/disable" switch. Ours was off and we couldn't switch it to Enable. However it gave a text box.
The MS engineer got us to copy the text, and we had to visit our Domain host (Go Daddy for us). And, in their DNS Management / DNS Records settings, under Cname settings, we had to enter some new components twice.
Your support engineer will take you through this.

Hope this helps you.

Cheers,

Answer 3

I have been having this exact issue now for 3 weeks. I opened a service ticket with Microsoft.

OP, please check what message you get back from your Microsoft server (the error email). Three weeks ago it was error '550 5.4.300 Message expired -> 421 4.7.28 [2a01:111:f400:fe5a::61d 15] - which is a bulk email error, even though the message was to only 4 Gmail recipients and was in reply to their message.

The suggestion my MS was that Google introduced a change, and is now unable to translate an IPv6 IP address for Exchange Emails, whereas IPv4 works, so they recommended I create an MX connector in my Exchange admin, you can find the instructions on Reddit. It is what the MS Help Desk told me. Create a connector and set for "lookup MX for domain", the idea is this forces MS into an IPv4.

I did this and it worked for a while, but stopped last week. Now some emails time out with a socket error returned '421 4.4.2 Connection dropped due to SocketError' whereas before they just timed out. This error implies a TLS encryption error I think, but not sure. Any admins here would be helpful.

To be clear, the emails are not bouncing, they are timing out because Gmail cannot/will not receive the email from O365.

Answer 4

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Answer 5

Anonymous

Hi,
Check if the sender is blacklisted. Have you tried using a different device?

Also please check if this helps:

421 4.4.2 Connection dropped due to SocketError

Regards

Shaofan

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Josh Weigner 1 Reputation point

2023-09-15T13:32:47.24+00:00

Experiencing the same issue since Wednesday with Exchange Online sending to Gmail. The link above is not useful as it pertains to on-prem Exchange servers.
Jim Hancock 0 Reputation points

2023-09-19T04:30:22.4166667+00:00

I have been having the same issue this month, September 2023. I am using Office 365/MS exchange and have been sending multiple contact emails using the same addresses for years with no problems until now. The Gmail addresses are always bounced back with the 421 4.4.2 Connection dropped due to SocketError' message. The only way around this is to send individual emails to one Gmail address. This is extremely frustrating. Please look into this. Thanks, Jim Hancock

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Mail Bouncing from MS Exchange- 421 4.4.2 Connection dropped due to SocketError'

6 answers

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