no
Members of Congress have the privilege of sending mail postage-free through the Congressional franking privilege. This privilege allows them to substitute their signature in place of a postage stamp. This special privilege is granted to members as a way to facilitate their official correspondence with constituents and other government entities.
Members of Congress are constitutionally granted certain privileges in order to carry out their work effectively. One such privilege is the speech and debate clause, which grants them immunity for any statements made during legislative proceedings. In addition, members of Congress are protected from arrest while attending sessions of Congress or when traveling to and from Congress, except in cases of treason, felony, or breach of peace. This privilege ensures that lawmakers can perform their duties without fear of interference.
Congressional Immunity What_is_congressional_immunity
franking .
It's called parliamentary privilege
Franking Privilege
Yes, they are immune.
The Franklin privilege, which is known now as The Franking privilege and which was introduced in 1775, allows members of Congress to send mail to their constituents at no cost to them. By affixing their name to the corner of an envelope where traditionally a stamp would go (a practice known as franking), Congressional representatives do not have to pay postage for mailings, a great cost savings to them.
Send correspondence to their constituents through the public mails free of charge
Franking privilege
Franking Privilege