https://support.mozilla.org/en-US/kb/signatures#w_signatures-stored-in-files

As every new email has a copy of your signature, modifying it and saving the changes are not anything more that using the File save as option on the menu.,

Matt, thanks for your reply but it doesn't answer my question. I've asked this particular question a couple of different ways and always get referred back to the page you referred me to. It does not address how to EDIT my signature html. I don't know how to do html. I can copy my existing file and paste it into the signature text, but of course, it strips out the html that is already there.

You do not need to know how to do HTML.

I'm presuming you have chosen to use a html file and it is selected here:

• Right click on mail account name folder in Folder Pane and select 'Settings' to open 'Account Settings' window.
• Select checkbox 'Attach the signature from a file instead'

NOTE: If you uncheck this then you will open a new Write message and there will be no signature, so offering you a clean sheet to start afresh - it is up to you.

• you clicked on 'choose' and the location and name of file is inserted. This is useful to know as you will probably want to save the new one in the same place.

I am presuming your account is set up to auto compose emails in HTML, so that when you click on 'Write' you see a 'Formatting Bar'. Whilst in 'Account Settings' for the account....

• Select 'Composing & Addressing'
• Select checkbox: 'Compose messages in HTML format'

Did you originally create the signature html file using Thunderbird? I'm presuming yes, because it is the easy way to it. However, I'm a bit perplexed as to why you do not know how to create a signature, which makes me think perhaps you were just given a html file and told to use it.

Click on 'Write' and the signature html file is auto inserted. This is where all the info in the link that Matt provided is helpful. At this point you can edit the signature in the 'Write' window in the same way you edit/compose any email you create. If necessary, just remove everything and start fresh, then you know it will not contain any bloated css html if someone created it using eg: MSWord.

Compose it exactly as you would like it. If you need to organise the signature then perhaps using a Table and inserting info into cells would help. If you have the -- signature delimiter showing, remove it. then when it looks exactly as you desire, save the file as a html file in the same place as you had it stored before.

• File > Save as > File
• Choose the location where to save it.
• Give suitable file name.
• Save as Type: HTML Files
• click on 'Save'

Finally, save as a draft and close the 'Write' window. Access the saved draft copy and select it so you now see what it would like. If something is not quite right, then 'Edit' the saved draft copy. Remove any -- signature delimiters and edit as required. Then do the File > Save as File routine. Once happy... Now make sure the Account Settings are set up to use that new html file and you are good to go.

The image below is just a quick example of using a Table, so the cells can help with positioning.

Thank you so much, Toad-Hall! Some of us just need a little more explanation!