I hereby acknowledge receipt of your letter of 25July.是什么意思？

I hereby acknowledge receipt of your letter of 25July.

特此告知贵方7月25日的来函收悉。

hereby

adv. 以此方式，特此；

例句
I hereby sentence you for life after all the charges against you have been proven true...
鉴于对你的所有指控都证明属实，我特此宣判你无期徒刑。

acknowledge

vt. 承认，鸣谢，对…打招呼，告知已收到；

例句
Most Canadians acknowledge that the aboriginal people have had a rotten deal.
大多数加拿大人承认土著居民遭受了不公平的待遇。

receipt

n. 收据，发票，收入；vt. 开收据，[美国英语]给…开收据，承认收到；

例句
She put the receipt into the innermost pocket of her bag.
她把收据放在提包最里面的口袋里。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

your

pron. 你的，你们的，尊，玉，乃；

例句
I think there's something a little peculiar about the results of your test.
我认为你的化验结果有点不对劲。

letter

n. 信，证书，许可证，字母，文字，字面意义；vt. 用字母标明，写字母于，加标题；vi. 写印刷体字母；

例句
Naylor acknowledged, in a letter to the judge, that he was a drug addict...
内勒在给法官的信中承认自己吸毒。