HOWTO - Create receive connector for Office 365

When using our Spam Filtering Service with Office 365. We recommend making two adjustments in Office 365:

  1. Creating a Connector
  2. Configuring Connection Filtering

Create a Connector

  1. Log in to your Exchange Admin Center in Office 365.
  2. Select mail flow and then connectors.
  3. Click the "+" to start the process:
  4. Define the mail flow scenario for this connector. Set From: to Partner Organizaion and set To: to Office 365:
  5. Name the connector and enter a description:
  6. Identify the partner organization by IP address:
  7. Click the "+" to start entering IP addresses:
  8. Use the list of CIDR networks found here: What IP addresses does ETRN deliver e-mail from? to enter the correct IP addresss:
  9. Requre TLS:
  10. Review and save the connector:
  11. Review your connectors:

Configuring Connection Filtering

  1. Log in to your Exchange Admin Center in Office 365.
  2. Select protection and then connection filter.
  3. Click the edit icon:
  4. Select connection filtering:
  5. Use the list of CIDR networks found here: What IP addresses does ETRN deliver e-mail from? to enter the correct IP addresss:
  6. Review your connection filtering:

 

We welcome any feedback. Thank you for being a ETRN customer. Please contact us if you have any questions.

We Answer Your Questions: FAQ

Q: What is the maximum e-mail attachment size?

A: The ETRN.com e-mail servers do not limit the size of individual e-mail attachments. The ETRN.com e-mail servers do impose a 400 MB maximum total message size limit. Individual customers can choose a smaller message size limit. We can also customize the handling of "over-sized" e-mails. Please contact us to discuss your specific needs. A couple of important facts:

1. Attachments are typically encoded in what is called Base64[1]. As a result, the actual length of MIME-compliant Base64-encoded binary data is usually about 137% of the original file size.

2. E-mails often contain both plain text and HTML components. This also increases the overall size of the e-mail.