Firstly - it depends on the email client - the one I'm most familiar with is Outlook.
Secondly, a JPEG or PNG from InDesign can be quite compressed and in my opinion not great quality.
I would export from InDesign to PDF and open in Photoshop - from here I'd save it as a JPEG with maximum quality.
Reason is, no matter what file format you use, when you insert the image file into Outlook it converts it to a jpeg, and the conversion is really lousy.
My ritual is
Design in InDesign
Export to PDF
Open PDF in Photoshop
Ensure size and resolution is correct
File>Save for Web
Choose Jpeg with Max quality
Insert that to the email signature
An email signature should be created in Photoshop and if it's just a simple logo, save it as a GIF file.
Thanks Eugene & Bob.
I will give exporting to Pdf and doing what you suggested Eugene.
Problem is I only have Indesign on my work computer, I do however have Photoshop on my own laptop at home so can give the importing pdf, exporting to jpeg a try at home.
Except in Outlook the Gif is converted to a jpeg with a horrible conversion.
There are free alternatives to photoshop - like GIMP which can be used for things like email signatures, but I wouldn't use it in any other capacity and especially not in a professional capacity.
I don’t use graphics for my signature but that’s good to know. Thanks.
Yes, I didn't know either, and I thought for a FB logo in a signature a .gif would be fine, and it looked great in the email before sending, but when the person received it it looked completely wrong. I then tried a 24 bit and 8 bit PNG to no success. On resaving the image from a received email it was jpeg. So I then insert it as a jpeg and sent it to myself and it looked good in email before and after sending.
Drove me mad. Everything I knew about graphics out the window.