I have an email program that is synced with a Salesforce campaign. Some of the program members that I'm sending the email to are not in Salesforce yet and all that I have for them is an email address (they provided an email address to receive my newsletter).
I'm concerned that Marketo will try to sync the leads to the Salesforce campaign, but won't be able to insert the lead into Salesforce since I don't have their a first name, last name or company name and that this will cause an issue.
Will this impact performance significantly? I'm fine with the leads not being synced I just don't want it to cause issues.