Is it permissible for a woman to talk to non-mahram men online with her husband's consent, and is the husband sinful if that is unlawful?

The internet is a tool that can be used for good or for evil. Chatting between men and women can lead to serious corruption and the destruction of homes, and it falls under the ruling of "those who take secret lovers" (mutakhidhaat al-akhdaan) whom Allah has forbidden to marry. Therefore, a Muslim must be careful of these websites and utilize their time in what benefits them.

This does not mean that speaking between the sexes is absolutely forbidden. What is permissible is allowed with lawful controls: no seclusion (khalwa), no softening of the speech, and the existence of a necessity or need to its extent. As for a woman speaking with her female friends (women) about permissible matters, it is allowed with lawful controls.

Forbidden speech (with non-mahrams without need, or in forbidden matters such as backbiting and slander) is unlawful even if the husband permits it, for there is no obedience to a creature in disobedience to the Creator. Permitted speech carries no sin, but one must be careful not to transgress the limits, neglect duties, open the door to unlawful acts, disregard the husband's rights, and lower the gaze from forbidden things.