Email undeliverable error

Occasionally, you might receive bounceback or undeliverable mail warnings while using Outlook or Office365 Mail.  Below will go over the most common cause of these.

Example:

If an email you send is undeliverable, you may receive a reply from Microsoft Outlook that looks like this: 

Note: Important portions of this bounce message are bolded.

From: Microsoft Outlook
Sent: Tuesday, May 23, 2017 2:26 PM
To: IMCEAEX-_o=First+20Organization_ou=Exchange+20Administrative+20Group+20+28FYDIBOHF23SPDLT+29_cn=Recipients_cn=bouncedemailaddress@namprd08.prod.outlook.com
Subject: Undeliverable: Bounced Message Subject

Your message to IMCEAEX-_o=First+20Organization_ou=Exchange+20Administrative+20Group+20+28FYDIBOHF23SPDLT+29_cn=Recipients_cn=bouncedaddress@namprd08.prod.outlook.com couldn't be delivered.
Your email program is using outdated address information for IMCEAEX-_o=First+20Organization_ou=Exchange+20Administrative+20Group+20+28FYDIBOHF23SPDLT+29_cn=Recipients_cn=bouncedaddress@namprd08.prod.outlook.com.
sendingaddress Office 365 IMCEAEX-_o=First+20O. . .
Action Required Recipient

Breaking Down the Jargon:

Sending Address:  sendingaddress
Sending Address Location:  Office 365 (In the Office365 Cloud)

Bounced Address:  bouncedaddress
Bounced Address Location:  Exchange (On-Premise Email Account)

If you'll notice, the error indicated above includes the phrase: Your email program is using outdated address information

This is a big indicator that your Outlook program has cached some old address information in its auto-fill that needs to be cleared. Luckily, doing so is incredibly easy!

Instructions:

  1. Identify the recipient who didn't receive your message by looking at the To or CC information located in the Original Message Headers section. Recipients whose names are followed by a set of characters that start with 'IMCEAEX' or 'imceaex' didn't receive your message.

  2. In the To box, start typing the recipient's name or email address until the recipient's name appears in the drop-down list.

  3. Use the Down Arrow and Up Arrow keys to select the recipient, and then press the Delete key to delete the Auto-Complete List entry.  You can also choose the X inside the Outlook application.

  4. Click New mail (in Outlook) or New Email (in Outlook on the web) and use the same X to clear the entry.

  5. In the To box retype the recipient's email address and resend the message.

If the problem continues or you don't think this is your problem, forward the bounce message to helpdesk@otc.edu.