Should Marketo create a new lead everytime an email address is changed in Salesforce?

It shouldn't be doing this.  If you delete the email address it breaks the synch with the corresponding Marketo lead, so don't delete the email address, save the record and then add the new email address.  If it is not that, check with Marketo tech support as to other possible causes.

Hey Karly,

I just asked tech support about this last week. I had a few instances where a contact in SFDC registered for a webinar using different email addresses and they were created as new leads.

After doing some research, it sounds like there isn't a great way for Marketo to de-dupe in this case -- at least that's what I heard. I did, however, use it as an opportunity to build a little alert system for myself using this tutorial from the community. It's not perfect, but at least helpful.

Is there any way to stop Marketo from creating a new lead everytime an email address is changed in Salesforce?

I have the same question. Was this ever figured out?