Signature image not appearing in email notification in Mac Mail

When I receive email notifications after a form submission, the signature image is not appearing even though other images do appear. I use Mac Mail, and I've checked the Preferences and confirmed that they are set to display remote images. This is a new problem - until recently, the signature image has always displayed.

Any suggestions?

I have checked your form and it seems like the signature image is sending correctly, I used a Gmail address: 

I'm not sure if there is anything on the email service provider you're using that may be blocking the JotForm domains, the image you used on the header of the email has a different address than the one used on the signature. 

I would recommend you to test with an address under a different email, you may also contact your email provider and ask if the JotForm domains are blocked, if so, you may request to have the following domains to be whitelisted: 

jotform.us

jotform.com 

jotformpro.com

I hope this helps.