Synonyms of the word

truly

• adv. In accordance with the facts; truthfully, accurately.
• adv. Honestly, genuinely, in fact, really.
• adv. Very.

genuinely

• adv. In a genuine manner; truthfully, truly.

really

• adv. (modal) Actually; in fact; in reality.
• adv. (informal, as an intensifier) Very (modifying an adjective); very much (modifying a verb).
• interj. Indicating surprise at, or requesting confirmation of, some new information; to express skepticism.
• interj. (colloquial, sarcastic, typically exaggerated question.) Indicating that what was just said was obvious…
• interj. (colloquial, chiefly US) Indicating affirmation, agreement.
• interj. Indicating displeasure at another person's behaviour or statement.

rightfully

• adv. In accordance with what is right or just; fairly.
• adv. Rightly, correctly.

sincerely

• adv. In a sincere or earnest manner; honestly.
• adv. (US) A conventional formula for ending a letter, used when the salutation addresses the person for whom…

unfeignedly

• adv. In an unfeigned manner; genuinely.