Change the following lines from
.Body = Replace(.Body, "[FirstName]", strFirstname)
.Body = Replace(.Body, "[ABM]", strABM)
.Body = Replace(.Body, "[ABMPhone]", strABMPhone)
to
.BodyFormat = 2
.HTMLBody = Replace(.HTMLBody, "[FirstName]", strFirstname)
.HTMLBody = Replace(.HTMLBody, "[ABM]", strABM)
.HTMLBody = Replace(.HTMLBody, "[ABMPhone]", strABMPhone)