How can I auto populate a signature in the bottom of a Sales Insight email?

not really unless you create my.Tokens in a program.
The out-of-box sales rep tokens is based on ruels in SFDC and how you've set up users and roles etc.

I suggest using My.Tokens and they can be updated by your marketo builder before launching a new program.

How would the my.Tokens know who is needing to send the email though? Would love to learn more about how you are considering piecing that together. 

My first instinct given that this is based on lead owner out of the box would be to create a bunch of signature using snippets and to basically clone the emails and have a naming convention specific to individuals that need to send out the emails. This would work for SMB but would not be very efficient at scale. 

You could create a custom text area field and then run campaigns which populate that field using the Lead Owner tokens combined with some HTML.
 

For Example:

Owner Signature as a custom text area field.

Run a campaign which filters by lead owner, and then in the flow have a Change Data Value flow step for Owner Signature, setting it to (for example):

<p><span style="font-size: 22px">Best Regards,</span><br>
<span style="font-family: trebuchet ms,geneva">{{lead.Lead Owner First Name}} {{lead.Lead Owner Last Name}}</span><br>
{{lead.Lead Owner Phone Number}}<br>
{{lead.Lead Owner Email Address}}</p>
<img src="http://www.yourdomain.com/SmilingImageOfSalesRep">

Then you could just reference {{lead.Owner Signature}} in the email. If you want to have different HTML for different lead owners, then just use choices or run a separate campaign. Keep in mind that this field is on the Lead/Contact object, not the SFDC user that Marketo looks up the Lead Owner information from, so it's important that it be up to date when you're sending out an email (so your leads don't see blank or incorrect signatures!).

Hi Paige,

What if you just created individual templates for each sales rep that were availible in sales insight that didn't use a token for the signature - you would just have

John - Following Up 1 
Matt - Following Up 1 

And they would only use their specific templates?

I guess that could get pretty intense depending on how many reps you have- but it could solve your problem?

-Ryan

Ryan, 

That's what I was trying to describe but your explanation is much more clear. 

- Jeff

@ Jeffery
I thought the question is how to send an email with a signature that does NOT come from the Lead Owner. 
Unless I read that wrong.

@Edward
I missed that - hence the problem with my solution I guess. Although the Salesperson could just edit it in SFDC I suppose and they could just use their name rather than the lead owner tokens. They would need to give time for the Marketo sync to pick up the change before sending their email though.