We do everything we can to catch common typos (like gmial.com), but we can't catch everything. Sometimes people just hit the wrong keys.
Here's the safest way to fix this:
Select Contacts form your Simplero Dashboard
Select All Contacts from the dropdown menu
In the Search field, enter your contact's name
Click on the contact and you'll be directed to the Contact Info page
Click the Edit hyperlink as shown in the picture below
In the Contact info page, type the new Email address
Scroll down to the Purchase and participant info section and check all the places that the email address needs to be updated
Click the blue Save changes button
While in the Contact Information page, scroll down to the Purchases section and select from the product list
Scroll down to the Participant section and remove the Simplero ID:
Also, if the switch next to "Emails:" says "OFF", which it might do if the email has bounced, switch it back to "ON"
Once that's done, you can send a new one
Once that's done, you'll see the new Simplero ID
We realize this isn't as simple as we'd like it to be, and maybe we'll come up with a good way to make it simpler in the future, but this is how you do it.