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, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
In principle, a Muslim should be given the benefit of the doubt. It should be believed, for example, that he is peaceful and wants good for others, especially for his neighbors - as long as he does not do things to cause others to be suspicious of him. Also, it is prohibited to have negative assumptions of others and we are commanded to avoid it.
Allaah Almighty says (what means): {O you who have believed, avoid much [negative] assumption.}[Quran 49:12]
Allaah rebukes those who follow negative assumptions for mere possibility and suspicion, saying (what means):
• {They follow not except assumption, and they are not but falsifying.}[Quran 10:66]
• {And they have thereof no knowledge. They follow not except assumption, and indeed, assumption avails not against the truth at all.}[Quran 53:28]
• {And you assumed an assumption of evil and became a people ruined."}[Quran 48:12], i.e. because of that negative assumption.
Also, the Prophet, sallallaahu ‘alayhi wa sallam, said: "Beware of suspicion, for suspicion is the worst of false tales." [Al-Bukhari and Muslim]
A Muslim should not harbor suspicions of everyone around him because some of them did something bad. This is a form of injustice on the earth. Allaah Almighty says (what means): {O you who have believed, be persistently standing firm for Allaah, witnesses in justice, and do not let the hatred of a people prevent you from being just. Be just; that is nearer to righteousness. And fear Allaah; indeed, Allaah is Acquainted with what you do.}[Quran 5:8]
Allaah, The Almighty, said in a Qudsi (sacred) Hadeeth: "O My slaves, I have forbidden injustice to Myself, and I have forbidden you from it, so do not wrong one another." [Muslim]
One of the most important tasks of Satan is to cause dissension between a Muslim and his fellow brothers. Allaah, The Almighty, says (what means): {Satan only wants to cause between you animosity and hatred.}[Quran 5:91]
Exchanging gifts and food among neighbors is permitted. It is also a means for love, affection and developing strong relationships and brotherhood. The Prophet, sallallaahu ‘alayhi wa sallam, said: "Exchange gifts and you will love one another." [Al-Bukhari in Al-Adab Al-Mufrad and Al-Bayhaqi. Ibn Hajar said in Talkhees Al-Habeer, 'Its Isnaad (chain of narrators) is Hasan (good).' Al-Haafith Al-‘Iraaqi said considered its Isnaad as Hasan in his revision of the Ahaadeeth of Ihyaa' 'Uloom Ad-Deen]
The Prophet, sallallaahu ‘alayhi wa sallam, said:
• "O Muslim women! None of you should look down upon the gift sent by her neighbor - even if it were the trotter of the sheep (fleshless part of legs)." [Al-Bukhari and Muslim]
• "And I shall accept the gift even if it were an arm or a trotter of a sheep." [Al-Bukhari]
• "Whenever a meal was brought to the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, he would ask about it. If it was a gift, he would eat from it." [Al-Bukhari and Muslim, the wording is Muslim's]
• "And he prohibited three things: gossip, asking too many questions and wasting money.” [Al-Bukhari and Muslim, the wording is Muslim's]
In brief, it is not permissible to throw food away and waste it because of customs or baseless suspicions. Throwing away food because of suspicions is a form of wasting wealth.
Accordingly, such women have committed two forbidden acts: harboring suspicions without evidence, and wasting money without cause. Another prohibited matter may be added to that: hurting a Muslim's feelings by rejecting his gift should he find out that it is thrown away in the garbage. Such things causes enmity and hatred among Muslims. We are forbidden from doing so and from doing what may cause that.
Allaah Knows best.