ד וַיִּשְׁלַח יַעֲקֹב מַלְאָכִים לְפָנָיו, אֶל-עֵשָׂו אָחִיו, אַרְצָה שֵׂעִיר, שְׂדֵה אֱדוֹם4. Jacob sent angels ahead of him to his brother Esau, to the land of Seir, the field of Edom.
And here is the Rashi (translations from JPS found on here):
ד וישלח יעקב מלאכיםמלאכים ממשJacob sent angels Heb. מַלְאָכִים, literally angels (Gen. Rabbah 75:4).
In the book of Shmuel I (Chapter 23) there is a similar Rashi on the following verse:
כז וּמַלְאָךְ בָּא, אֶל-שָׁאוּל לֵאמֹר: מַהֲרָה וְלֵכָה, כִּי-פָשְׁטוּ פְלִשְׁתִּים עַל-הָאָרֶץ27. And a messenger came to Saul, saying, "Make haste and go, for the Pelishtim have spread out over the land!"
And here is the Rashi:
כז ומלאך בא אל שאול - מלאך ממש כדי להציל את דודAnd a messenger came (Heb. ‘malakh’) a real angel, in order to save David.
I believe, (based on a Bar-Ilan query) that these are the only two instances in which Rashi makes the point that malakh is referring to an angel as opposed to a more mundane messenger (of the human variety). The context in the book of Shmuel is highly instructive. David has been surrounded by Shaul and his men – his fate is certain, there is no escape. At the moment when all hope has been lost for David a messenger comes to Shaul sending him off to defend his nation from an onslaught of Pelishtim. A sensitive reader knows that the verse could just have easily told us that a man came. The reason for saying a malakh came is clear. David was saved, not by chance, but by divine intervention. The 'messenger' is an 'angel' – this is the text's way of telling us to not view this event as mundane. Clearly, Rashi is not trying to tell us that a metaphysical being came with the message to Shaul.
With this in mind, one should consider what Rashi means in Parashat Vayishlach.