I have done educational / activist speaking where it was necessary and right that I reveal that I am a Transsexual Woman. There were men in the those audiences who were interested in me because of what I told them, but only from the standpoint of their wanting to be better informed about TS women and men, and not because of wanting sex with me. In time there may be one who wants to continue a relationship, but it has not happened yet. As for sex, I spent many years as a CD, and in those years there were "admirers" who wanted sex with a pre-op and or non-op, and knowing my birth gender was important to them. (They were a total turnoff to me however, and so, no business.)
I know, I have not answered your question either, and maybe this post might even be off topic and you will want to have a moderator kick this one, but none of us Post op can give you much help, unless it is some of the real long timers with several years or decades. If lack of certainty of how you will be taken as post op is really bothering you, check with your therapist, and maybe hold back on your letters for a while.
If you find a person you are afraid to tell the truth to, then don't have sex with them. If you are not afraid to tell them, then play it by ear, it could make the situation better, worse, or no change. I am not a prude, just a pragmatist. If you have no fears of them, it will depend on the depth of the relationship and its purpose in your share lives. Need to Know security as opposed to a right to know.
