Thanks for your help, that looks to have fixed it!

Thanks for your replies. Javier: That would be an excellent idea, but usually we get contractors calling us independently, going through different sales reps and often not giving us much, if any, information on the job they are getting a quote for. If there is no other way, then your idea may be a solution. One thing we do…

Unchecking the signature and clearing the cache worked for us too. As a bonus we found that when we compose an email the signature is not there, but if we preview it, the correct signature is in place!

We are also having the same issue. Netsuite email is coming up in plain text with the formatting showing. It is affecting most, but not all users. Unfortunately it is affecting our sales department, so this is a big issue.