Hi Shane,
Yes you can change your Default Email Preferences in Method CRM by clicking on Customize > My Account > and then click on the (view / edit...) link next to Default Email Preferences. Finally, add the outgoing (SMTP) information for the mail server you would like to use. This can easily be found by performing a Google search. Since you mentioned Gmail I included the information for you in the screenshot below. The only thing you shouldn't copy are the Usern Name and Password I used; you need to use your credentials 
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Finally click Save & Send Test Email.
- Ashur
Need more help? Ask us about Method consulting services
Ashur Shamon
Lead Solutions Specialist, Professional Services
Method Integration Inc.
www.method.me
Toll Free: 1.888.925.6238
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Fax: 416.640.6027
E-mail: a.shamon@method.me