Maximum number of connections from user+IP exceeded

Question

Hi there,  
  
We desperately need some help with the following error:   
"Maximum number of connections from user+IP exceeded (mail_max_userip_connections=5)"  
  
We run workmail for our business. Our employees access have set up access to workmail email accounts on multiple devices (primarily Apple devices). When we're on the run, we work from the phone or laptop. When we're stationary, we can use laptops and workstations ...  
  
I for example, access my email account from my iMac, iPad and from my MacBook. Maning that I've set up an email client in Mac Mail on all devices, to access the same WorkMail email account. Everything use to work fine until about a week ago, when we started getting the following error "Maximum number of connections from user+IP exceeded (mail_max_userip_connections=5)". Other employees are experiencing similar issues.  
  
I'm guessing from what I've researched, this is an email server setting, related to IT Security controls, etc. It basically limits how many connections can be established from the same IP ... In this instance though it is preventing us from carrying out work.   
  
Is it possible to increase this setting from "5" to say "30". If so, How do I go about it in WorkMail / AWS (yes, have searched far and wide, with no help)?   
  
Any help greatly appreciated !

Answer

Hi Dan,  
  
As long as I don't lose any emails, I will try this.   
  
Cheers,  
Steve

Answer

The limit has been increased to 10 concurrent connections from the same IP address. Please note that making more connections doesn't necessarily give you a better experience.

Answer

I have been also suffering from this error since around Sep 8th.  
I can't use Exchange in my application, so I reduced the connection environment.  
  
I think the global settings on the WorkMail have changed recently.

Answer

Hi JohnK,  
  
Increasing the limit ('m assuming this is a global setting that has been tinkered with lately on the workman server end?), appears to have fixed some of our (extensive) connectivity issues. Although, the problem appears to have resurfaced in the last day or two ...   
  
I will try Dan's suggestion RE: connecting via ActiveSync (or Exchange) instead of IMAP, but I need to perform relatively extensive research first - to understand impact (on existing email clients, locally archived emails, etc). What's the drive to minimise connections from the same IP address (for IMAP only?). Is it security-driven? In either case, 5 or 10 connections from a single IP address may still be a little low - especially for use cases where administrators or office managers may administer (and access) multiple email accounts.

Answer

Any idea if this limit can be raised ?  
i have 3 devices myself connecting behind a NAT firewall and other members of my team are also at the same location.  
I do not use outlook or activesync on any of my devices  
  
Ken

Answer

From the error message you're seeing, it seems you are using the IMAP protocol on all these devices. We generally recommend you use the Exchange protocols (ActiveSync for iOS devices, and EWS for OSX) to access mail if your device supports it as those do a better job handling multiple connections for the same mailbox.  
  
When you configure mail on your device, you should be choosing the "Exchange" account type. See our guides to setting this up:  
https://docs.aws.amazon.com/workmail/latest/userguide/connect_mac_mail.html  
https://docs.aws.amazon.com/workmail/latest/userguide/mobile-client.html

Maximum number of connections from user+IP exceeded

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