Assalaamu Alaikum,
InshAllah this email reaches you in the best of Iman.
You must remember that when others are speaking about you in your absense, Allah SWT is defending you, without you knowing about it.
Also when people backbite/slander you, their hasanat (if they have any) is taken away from them and given to you. If they dont have any hasanat, then a sin that you may have committed is taken off you and added on to their list SubhanAllah.
People who partake in this sin must not realise just how bad this is for them in this world and in the akhira as it all comes back to them in the end.
So really, its sometimes a good place to be - having someone speak about you, while you collect their hasanat - this is providing that you do not retaliate and do the same back to them. (Good reminder for us that we shouldn't be backbiting/slandering someone)
I cant quite remember the exact reference to the Hadeeth where a Sahaba found out someone was speaking about him in a negative sense, and so he sent this person a bowl of grapes with a note saying "thank you for your hasanat". I think thats wonderful! In fact we should probably do the same to these types of people to let them know what they have just done.
So, as upsetting as it is to find out someone has spread rumours about you, inshAllah just remember that Allah SWT is defending you in your absence.
And your hasanat bank is growing.
And Allah SWT alone gives success.
Was Salaam