MS CRM The length of the 'messageid' attribute of the 'email' entity exceeded the maximum allowed length of '100'.

I had noticed that this error was logging in the Application log of our CRM server very often.

#9628 – An error occurred while delivering the e-mail message with subject "FW: Undeliverable: Read: " in mailbox email@ourdomain.com for delivery to http://localhost/CRM. System.Web.Services.Protocols.SoapException: Server was unable to process request.
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at Microsoft.Crm.Sdk.Proxy.CrmService.Execute(Request Request)
   at Microsoft.Crm.Tools.Email.Providers.CrmPollingMailboxProvider.DeliverMessageInternal(EmailMessage emailMessage)
   at Microsoft.Crm.Tools.Email.Providers.ExchangePollingMailboxProvider.DeliverMessageInternal(EmailMessage emailMessage)
   at Microsoft.Crm.Tools.Email.Providers.CrmPollingMailboxProvider.DeliverMessage(EmailMessage emailMessage)
   at Microsoft.Crm.Tools.Email.Providers.CrmPollingMailboxProvider.Run()rn
0x80044331
A validation error occurred. The length of the ‘messageid’ attribute of the ’email’ entity exceeded the maximum allowed length of ‘100’.
Platform

The solution was to customize the Email Entity.