I have been Islamic activist for last 25 years. By profession I am a lawyer. I am the founder of Centre for Islamic Studies- vision+mission taking Islam to non-Muslim. I am also the founder of Amal International School currently 1000 students are studying. My friends working with me for the last 20 years carried on a campaign to get rid of me which I resisted. Now I am in control of both places. My friends are now carrying on a campaign of anonymous letters involving me my family. I know this is something not permitted in Islam. I need a detailed fatwa on this issue to be carried in our "The Choice" Anonymous letters fall under the category of backbiting. During the time of our Prophet nobody resorted to this method since very few new to read and write. What is going on now is a modern day phenomenon. Please do help me since I am not a Islamic Scholar.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

First of all we ask Allaah to greatly reward you for your efforts in spreading Islam and teaching Muslim children. Unity is among the best ways to spread Islam. Allaah says (which means): {And hold fast, all of you together, to the Rope of Allaah (i.e. this Qur'an) and be not divided among yourselves.}[Qur'an 3:103]. Division is a major hindrance in spreading righteousness and piety. Allaah says (which means): {… and do not dispute (with one another) lest you lose courage and your strength departs …}[Qur'an 8:46]. The Prophet said: "Spoiling the relations between people is the destructor (i.e. destroys ones religion)." [At-Tirmithi] Another narration reads: "Spoiling the relations is the shaver. I do not mean that which shaves hair but which shaves one's religion (i.e. ruins it)." So we advise you to unite, be on one rank, and bear the responsibility put on your shoulders. Besides, you should endeavour to reconcile between you while seeking the pleasure of Allaah, as when Allaah sees that a person is sincere, He enables him to achieve his goal. Allaah says (which means): {If they both desire reconciliation, Allaah will cause it between them.}[Qur'an 4:35]. There is no harm to seek the help of righteous and pious people and anyone whom you think could play a role in reconciliation, as Allaah could make him a means of reconciling your differences. We believe that all of you will be happy to achieve reconciliation.

You have to remember that such problems in a country where the Muslims are a minority could drive people away from Islam and prevent them from embracing it. On the contrary, you should be a good example for them and be friendly and affectionate among yourselves as Muslims, so that this would attract them to embrace Islam.

If what you have mentioned really happened that your colleagues are spreading rumours against you, we advise them to fear Allaah regarding, their brothers and their religion. Allaah says (which means): {O you who believe! Keep your duty to Allaah and fear Him and speak (always) the truth.}[Qur'an 33:70]. Allaah further says (which means): {And say to My slaves (i.e. the true believers of Islamic Monotheism) that they should (only) say those words that are the best...}[Qur'an 17:53]. These people should know that spreading rumours is not a characteristic of believers, rather it is a characteristic of hypocrites, Allaah says about the incident of the obvious lie about 'Aa'ishah (which means): {When you were propagating it with your tongues, and uttering with your mouths that whereof you had no knowledge, you counted it a little thing, while with Allaah it was very great.}[24: 15].

Even if we suppose that a Muslim had committed some sins, in principle we should conceal his sin and should advise him, and not spread his sin and despise him.

Backbiting a Muslim and mentioning his evil deeds, is spreading evil. Spreading this orally is forbidden and it is also forbidden through other means like anonymous letters and the like. 

Allaah knows best.