The Muslim web site http://www.erols.com/zenithco/ has the clear goal to spread Islam by showing the attractiveness of Islam regarding the essence of its message and the reality of its history, to convince non-Muslims of its truth and to invite them to accept Islam as their own religion. These are good goals and one cannot object. Every believer will want to tell the best about his religion and convictions. Nevertheless, invitation to any religion should only be done on the basis of truth, not fraud. I am sure, most Muslims would agree with this principle.
In a section containing various articles on the person and prophethood of Muhammad we find the article "Prophet Muhammad in Parsi Scriptures" and in it the following claims:
The Epistle of Sasan I in Dasatir contains the prophecy about Prophet Muhammad. Sasan I was a reformer of the Zoroastrian religion. It is believed that this Epistle is a part of the teachings of Prophet Zoroaster, to which Sasan I added his explanatory notes. Some scholars have suggested that the word `Dasatir' means ten (das) parts (tir) while others contend that this word is derived from Dasatur, meaning religious law. The Zoroastrians are also known as `Magians' and `Fire Worshipers.' The Epistle of Sasan I describes future events at a time when Zoroastrians will have forsaken their religious practices. The English translation of the Epistle of Sasan I is presented below. "When the Persians will do such deeds, a man from among the Arabs will be born whose followers shall overthrow and dissolve the kingdom and religion of the Persians. And the arrogant people (Persians) will be subjugated. Instead of the temple of fire and the house of idols they will see the House of Abraham without any idols as their Qibla. And they (Muslims) will be a mercy to the worlds. And they will capture the places of temples of fire, Madain (Ctesiphon), nearby lands, Tus and Balkh, and other eminent and sacred places (of Zoroastrians). And their leader (Prophet Muhammad) will be an eloquent man whose words and message will be clear and far-reaching." The word by word translation of the Epistle of Sasan I is given below. The text of this Epistle is taken from Dasatir published by Mulla Pheroze during the reign of Shah Nasiruddeen Kachar of Persia. Mulla Pheroze lived in Bombay (India) and he was an eminent scholar of Pahlavi, Zend, Persian, and Arabic languages. He consulted with several famous Zoroastrians priests to authenticate his translation. The original text is in Pahlavi.Many other Muslim pages either copied the above into their own site, make the same claim in slightly different words, or link to a site making the claim: , , , 
Should Muslims intend to uphold this "prophecy" they need to put some effort into authenticating the document itself, i.e. its age and content, not only the accuracy of the translation.
We have inquired with a scholar in the field of Zoroastrianism and early Persian texts and were given this information:
... you are entirely right in suspecting the authenticity of the 'Epistle of Sasan 1'. The 'Desatir', from which it is cited, aroused a great deal of interest among Parsis and in the academic community at its publication, because it contained much remarkable material, but as soon as it was the subject of serious scholarly investigation it was established, on the basis of language and contents, that it was a literary forgery. It is thought to be the product of some Persian Sufi school, with only the most tenuous connection with Zoroastrianism. The spuriousness of your particular passage is instantly apparent, because there was no Sasan 1. "Sasan" was the eponymous ancestor of the Sasanian royal family, but nothing is known about him, and the name was never borne by any king of the dynasty. A whole succession of obscure "Sasans" were, however, invented to link the historic dynasty with the legendary Kayanian dynasty of the Zoroastrian 'Avesta' [prayer book of Zoroastrianism], and so the name occurred in semi-mystical writings, and would readily have been picked up by the unknown author of the 'Desatir'. There is no reason to suppose that the text of an 'Epistle of Sasan 1' existed outside that work.
The fact that there never was a "Sasan I" can easily be confirmed through the Encyclopaedia Britannica, the article "The History of Ancient Mesopotamia - THE SASANIAN PERIOD".
A non-existing Sasan I can obviously neither be a reformer of the religion of Zoroastrianism, nor could he have uttered prophecies about Muhammad.
On June 11, 1998, I sent a message to the web master of the site carrying the discussed article containing part of the above information. My message ended with this paragraph:
From: Jochen Katz <firstname.lastname@example.org> Date: Thu, 11 Jun 1998 03:47:18 -0400 (EDT) To: email@example.com Subject: Prophecy of Muhammad in Parsi Scriptures? ... If there is any evidence (scholarly) for its authenticity could you please inform me about it? Are there any scholarly articles in academic journals that discuss this source and which uphold its authenticity? What are the critical views about it? Why do you (Dr. Zahoor or Dr. Haq) believe it is true? Should you find out that it is a hoax, would you withdraw it from your site?
I have not received any response. The article remained on the site unchanged. Therefore, this web page went online to expose the hoax, June 25, 1998, two weeks after the above inquiry.
Rumors and Hoaxes
Was Muhammad foretold in prophecy?
Answering Islam Home Page