Event Email Not Sending Error Due to MapiExceptionSendAsDenied

Released Date: 08/26/2026

Version: 8.5 & Up

Q - I am testing Elliott Events again to try to utilize it. Many years ago, we used some but those have stopped working. I have at least one that seems to be working now but others are not. I just checked the Email Log and in the <ElliottRoot>\Log\01 folder I found all of these errors which seem to be part of the problem. I need some assistance with these errors. Does it have something to do with the Send email address? I am attaching the full log for this month to show all the errors.

A - We looked at the first entry of your errors, and it has the following text:

RETRY1: Email Error with these parameters:

Server=smtp.office365.com:587

Authname=accounting@tandemloc.com

From=ARI MELTZER <ari@tandemloc.com>

To=mary@tandemloc.com

Enable SSL/TLS with SecurityProtocol=Ssl3, Tls, Tls11, Tls12

Ignore Certificate Error

Transaction failed. The server response was: 5.2.252 SendAsDenied; accounting@tandemloc.com not allowed to send as ari@tandemloc.com; STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message [BeginDiagnosticData]Cannot submit message. 1.84300:0A000000, 1.84300:0A000000, 1.84300:0E000000, 1.84300:32000000, 1.73948:00000000, 5.71140:67000000446F526F70730000, 1.108572:00000000, 0.117068:56000000, 1.79180:0A000000, 1.79180:0A000000, 1.79180:0E000000, 1.79180:32000000, 1.79180:FA000000, 255.73100:00000000, 5.95292:67000000446F526F70730054, 8.111356:9552F9FE86593ECC1F1F572B2F8F6BAC44B8F452, 0.38698:80DEE83A, 1.41134:86000000, 1.98628:00000000, 1.41134:46000000, 1.98628:00000000, 0.37692:150F0E81, 0.44092:150F0E81, 0.41232:150F0E81, 0.60208:2C000000, 0.37136:44000000, 0.34608:86000000, 0.55056:0F010480, 0.42768:86000000, 0.56112:86000000, 0.52807:23000000, 0.46663:8D000100, 1.41134:46000000, 1.98628:00000000, 7.36354:010000000000010901000000, 1.46439:0A000000, 1.115228...

I assume all the other error messages are similar. Please verify. This message is saying that you are using the account accounting@tandemloc.com to authenticate with your SMTP server (Microsoft Exchange online or Outlook/Office 365). You are trying to send an email where the send from is ari@tandemloc.com. But your SMTP server does not allow this for security reasons and typically is to prevent SPAM.

Just imagine a user is authenticated on one email account, and he/she can send out tens of thousands of emails and claims to be someone else. You can see that is a security problem for sending SPAM email, right? This “SendAsDenied” is a complicated subject. I am including the following KB articles for you to digest:

https://support.netcellent.com/portal/en/kb/articles/pdf-postoffice-emails-are-rejected-by-server-for-some-users

https://support.netcellent.com/portal/en/kb/articles/feature-8-6-email-improvements-multiple-email-servers-universal-throttling-send-from-priority

You have a couple of options to resolve this "SendAsDennied" restriction:

Do not use one common email account to authenticate. Use each individual user's email account to authenticate them so there's no authentication and send-from mismatch issue. That is to say, when send out the email, if the from email is ari@tandemloc.com, then the authenticate account should be ari@tandemloc.com too. This is something you can do yourself.
Send up rules on your SMTP server so the accounting@tandemloc.com can send an email on behalf of other uses in your organization. You need your IT involved here.
Use an SMTP server that’s less strict on this “SendAsDenied” rule. For example, you can use SendGrid as your SMTP server. If you use Microsoft Exchange online or Office 365, they are much stricter on this rule because they want to protect their reputation. SendGrid's reputation is not as good as Microsoft, so your email sent by SendGrid may go to the user’s junk email folder. Therefore, you have to tell your recipient to “un-junk” your future emails. If you'd like to go this route, you need to get together with your IT. Once you have the SendGrid account, we can help.

Each solution is not perfect -- you need to pick your own poison.

Option #1 Example

If you don't host your own email server (e.g., in this case, you use Office 365), we think option #1 is the easiest way to proceed. If you go to each user desktop, on the Elliott Control Center, choose "Setup" -> Misc. tab, -> Email Settings button. Set up your Email Preferences similar to the following screen (this sample screen is for Elliott 8.6. Elliott 8.5 screen looks different):

In this screen, instead of using a default SMTP server where everyone authenticates with one common email account, you let each user use an "Alternate SMTP Server" and let each user authenticate with their own account. If you do so, then there will be no "Authenticate" and "Send As" inconsistency, and this will resolve your email server limitation.

EMK