If several leads/prospects share 1 email address like info@ will they get the email message more than once?

If the lead was created in SFDC and there is 3 lead records using the same email address (info@) then 3 leads come over to Marketo. If all 3 are added to a smart campaign to send an email, only one email will go out! (can't do much prevention when leads use a distributed email address like info@, who knows how many emails address sit behind info@).

Set for 1 email address per activity not lead. Same for uploading leads in a CSV file, if you have dupes, they will get merged into one record.

Marketo won't create dupes but will accept a dupe from you SFDC.

Edward, then how does Marketo decide which of the 3 should get the email?

My understanding was that if you have 3 contacts with the same email address:

1. John info@email.com
2. Katy info@email.com
3. Ben info@email.com

Then info@email.com will get 3 emails in the same mailbox:

1. "Hi John,"
2. "Hi Katy,"
3. "Hi Ben,"

If not, then which leads gets it, and which don't?

Thank you both so much for your timely weighin on this question!! I am looking forward to hearing the final peice to this puzzle that Grant referenced for me. 

My understanding is that when there are duplciate leads based on email address, only one email will go out, and it will be sent to the lead that was most recently updated. So in Grant's example, if John has the most recent update date, one email will go out to info@ and any tokens will pull John's info.