Emails in Filemaker can frustrating (I assume you use Windows, MS Office, and FMP 12). Single emails are easy, for the most part.
You can send email through an email client (Outlook, Thunderbird, Mail.app) or through the SMTP server built into OS's.
Microsoft limits the inferface between Outlook and other applications.
There are plugins for Email in Filemaker that can make things easier. http://filemaker-plugins.com/compare/email-plugins/
This is my collection of Email in Filemaker Links
Send Email from File Menu in FileMaker Pro | FileMaker
Send Mail via SMTP in FileMaker Pro 10 | FileMaker
Support for Sending Mail via an SMTP Server vs. an Email Client | FileMaker
How to Go to a URL from FileMaker Pro | FileMaker
Entering or editing SMTP options
Sending one email message
Send SMTP email tester
FileMaker Send Mail Script Step | Dwayne Wright
Sending Email via FileMaker and Gmail
Email Plugins Comparison - FileMaker Plugins
Mail to FileMaker Importer | Automated Workflows, LLC
Sending HTML Email from FileMaker | the beezwax buzz
MailChimp Integration with FileMaker Pro – Part 1 of 3 | HomeBase Software
FileMaker and MailChimp Integration by Douglas Alder on Prezi
What are the email sending limits of ISPs and other providers?
Email Client Popularity | Campaign Monitor
This is my collection of Basic Filemaker Links