When to utilize the features of PoliteMail lists.

Q:  Is there a maximum number of email addresses that can be added to the
“To, Cc and/or Bcc” fields of an Outlook email message?
A:  There is a maximum of 500 recipients (email addresses) in Outlook 2016/Office 365 version.

Does this matter if I am using PoliteMail?

Yes. PoliteMail was intended to send internal electronic communications to large global distribution lists or PoliteMail lists. Cutting and pasting many email addresses (500+) into any of the sending fields of a tracked message can cause mail flow problems, including failure to send.

In addition to the maximum limit of 500 recipients, Outlook adds the list of recipients to the message header, increasing the size of the message. Previous versions of Outlook limited the size of the message header/recipient list to 29k instead of having a maximum number of recipients.

If you are working with a large group of recipients that are not easily available through your Global Address list, you can upload a .csv file to create a PoliteMail list, containing all the recipients. Please note that since PoliteMail lists are created manually, they are not updated automatically. Due to this you may want to upload a new .csv file each time you want to send to the list.

An added feature of using PoliteMail lists is the ability to create and utilize custom fields. Custom fields can be utilized like mail merge fields when sending messages to PoliteMail lists that contain the custom field(s). Any custom field(s) would need to be included in the spreadsheet and defined in PoliteMail prior to uploading the .csv file. See this article for more information on custom fields and contacts.

To create a .csv file from an Excel Spreadsheet:

  1. Remove any extra data and save the excel file as a single page excel fileKBExcelSS
  2. From the File menu choose ExportKB_Export_CSV
  3. Choose Change File Type and select CSV and click Save As
  4. Save the .csv file to a place on your computer that you will remember

How to upload a .csv file to create a PoliteMail list:

  1. Click on the PoliteMail tab in your main Outlook window
  2. From the Lists drop down menu choose Mailing Lists
  3. From the Import drop down menu choose CSV
  4. Select the .csv file from your computer and click on OpenKB_Import_Contacts
  5. Within the Import Contacts window type in a New Mailing List Name – We recommend a name and date (PM lists will display in alphabetical order in your message window)
  6. Leave the Contact Owner drop down set to All Users which is recommended (private contacts should only be set if the contacts will never be utilized by anyone else sending with PM)
  7. Click Next
  8. You will need to map the fields – you only need the email address for the list to work, but may want the First and Last Name if using the personalization feature in PoliteMail.
    If you are utilizing custom fields, once they have been added to PoliteMail under Settings > Custom Fields, you will be able to map them here.KB_Map_Import
  9. Click Import
  10. You will get a message when the list is successfully imported with the total # of contacts that were imported. PoliteMail will remove any duplicates or bad/blank email addresses.KB_Import_Sucessful
  11. Click Close
  12. The new list will now appear within your list records.
  13. If you want other users to access the list you will need to share the list by selecting the list and clicking on Set Sharing > Shared from the Actions pull down menu
  14. To access the list within an email message click on PoliteMail > Send To List and select the PoliteMail list (displayed alphabetically)KB_PM_Lists_Pulldown
  15. The selected list will be placed in the “To” field automatically. It can be pasted into the “Cc” or ‘Bcc” field.


You can now send a tracked message to the newly created PoliteMail list, without exceeding any Outlook header or email address limits.


Written by Rose Censullo, October 2017