Are you asking how to type "_" ?

If so, hold down the shift key and then press the key directly to the right of the zero key; kind of above the letter p.

You didn't solve my problem. What you recommended just inserts an underscore separately. I need an underscore under a letter. In Microsoft word you have to highlight the letter you wish to be underscored and then press the underscore key.

Maybe you should ask your client who has this underscored character in his email addy how to type it in - are you sure that it is correct and meant to be in the addy? ... I have never come across this before

I met my client last night at my gym. The client is the economic minister for Guiana. He said he uses shift underscore but that doesn't work. He then gave me an alternative address but that address was rejected. I may have to give him a paper copy of my report.

Can you paste that character here?

It is possible that it is a special Unicode character and not an underlined character.