How are you entering the data into emails? Typing them directly into a new message, attaching them as a separate file, or copying them from another application?

The numerical data is typed directly into an email message

Does the message look correct in the Sent folder? Under Tools/Options/Display/Formatting/Fonts & Colors/Advanced, what do you have for Text Encoding: Outgoing Mail?

Text looks OK in sent folder Text encoding in outgoing mail is set at UNICODE (UTF-8)

That would suggest the problem lies with how the recipient has set their encoding for incoming mail.

Looking more closely at the problem, it looks like the recipient is receiving the alpha and numerical text, but the spaces btwn these two are filled in with weird symbols such as shown below.

   Boiler chemicals & maintenance��������������������������������� $1,000������������ $1,000
   Building insurance���������������������������������������������������������� $5,500������������ $5,500�

Are you by any chance sending through an ATT or Yahoo account?

Some other posts that may be helpful:

https://support.mozilla.org/en-US/questions/1193450#answer-1074022

https://support.mozilla.org/en-US/questions/1197969#answer-1059502

I am sending through a yahoo account

Try the workaround mentioned here: open Tools/Options/Advanced/General/Config. editor and double-click the preference mail.strictly_mime to set it to true, OK to close Options.

After the config editor I could not find a listing for

preference mail.strickly_mine

Is this listing correct?

JimOakley said

After the config editor I could not find a listing for preference mail.strickly_mine Is this listing correct?

It's not mail.strickly.mine Look for mail.strictly.mime

Thanks for all your help, you have solve my email problem