It's not that you are either the sender or the receiver, but rather that in the two distinct interrelated functions of sending and receiving, of submitting to interpretation and interpreting, there are associated distinct subjects which being incommensurate are only formally identified as a single 'self'. In your thoughts or actions as utterances you hold the context of reception as a fixed point outside the vanishing subject who brings the words or actions up out of nowhere, while in your reception of novel experience you hold the event in its novelty constant and shift around the receptive stance according to the needs of the vanishing subject. There are the ways this subject appears to appear, but it is not one subject, is two subjects and within each of those many more differentiated instances. This hiatus is what it taken to be evidence for 'no self', and the evidence is low-hanging enough that you can 'prove' it again and again, ad nauseam. Actually, if a subject is called for by these schemata it is not the vanishing points but what it is that in each case you mistake for that subject. It is what gives you the idea of being able to treat them as if they were the same thing. It's an impossible knowledge which you nonetheless possess but which no such functional 'self' can ever come close to.