I have a recent client who wishes to have a tailor made email signature. Amazingly enough I managed to pull off a responsive email signature, however, the client wishes to control the body text of the email.
By placing HTML body stles, I controlled this on the client’s level, but unfortunately the recipients do not get the changed email signature body text.
Has anybody had experiences of this before?
Once the email is sent, the sender has no control over what happens to the email or how the code is interpreted.
IMHO, signatures should be kept simple. Name, position, company, logo, and contact information.
Keep in mind that not everyone uses HTML email–a lot of people still use plain text.
I think you’re completely right. I have a responsive email signature. It’s basic with a logo, name and address, but it changes when resized. I used Email on Acid to make sure it renders correctly and it works well. The only issue is the client is asking for things that aren’t possible, and wants me to change the text and font color of third-party email clients. 
Time to educate the client a little bit about the world of email clients 
educating clients, is there no easier option.
Well, you could change the nature of the internet and require every single email user to use the exact same email client. 
To illustrate the differences between clients, set up email accounts with outlook.com, yahoo.com, gmail.com, aol.com, and any others you think might be useful.
Then, send yourself an email to each one with the signature you created. Take screenshots from each email provider, and show them to your client.
That should help illustrate that there is a host of differences between each email client without too much extra work.
Thanks for all your help. I have explained this to the client, so hopefully he can agree to disagree. The cons of this job are that clients are clueless to the most part on what we do, which is why explaining can be difficult. I recently had a client ask me what a domain is. Not sure if he was being silly, but there you go. Another one asked me how is my email connected to my domain. This is where patience comes in.
Usually when that happens, I just launch into “teacher mode”. It’s helpful to have some metaphors handy to help explain things in analog or real-world terms.
Try equating building a website to building, filming, and producing a TV show and advertising it.