I don't use this application, but I have two database apps at work that track contact information. There's only one email field, but sometimes we need to notify a second person (like an assistant). In both situations, we simply type two emails separated by a semi-colon. It works just fine when merged into emails for us and we've used Groupwise and Outlook email systems. We also do this when we set up spreadsheet lists and only have one column for an email.
Does the field do an email type validation? If not, can you not simply list both emails with a comma or semi-colon in between? That works in many fields, although I'm not familiar with specific program.
The system only allows one email address per volunteer so your workaround is the only way to accomplish what you want. We can certainly add that request to our list of potential enhancements.
Is there a way to have multiple e-mails for a volunteer? I have numerous volunteers who desire to get the e-mails at home and work, and having to add them a second time just so they could receive an e-mail at both seems inefficient.
If not this seems like an obvious improvement idea.