This article explains how to insert multiple email addresses into the To: header field, or how to use the Cc: or Bcc: fields to add more recipients. When inserting multiple email addresses into either of these header fields, make sure to separate them properly.
How can I send an email to multiple recipients separately from Microsoft Outlook?
Most — but not all — email clients require you to use a comma to separate multiple email addresses in one of their header fields. For these email providers, the correct way to separate email addresses in the header fields is:
and so on. For nine out of ten email clients, commas are the solution. They work fine, unless you're using Microsoft Outlook. Some email clients, like Gmail for Android, accept both commas and semicolons.
Outlook and any other email client that searches for names in the lastname, firstname format, using commas as the delimiter, may have problems if you separate email recipients with commas. Email clients that use commas as the delimiter typically use semicolons to separate multiple addresses in their header fields. Outlook defaults to entering multiple addresses using semicolons as the delimiter.
