The envoi is relatively fluid in form, depending on the overall form of the poem and the needs and wishes of the poet. In general, envois have fewer lines than the main stanzas of the poem. They also repeat the rhyme words or sounds used in the main body of the poem. For example, the chant royal consists of five eleven-line stanzas with a rhyme scheme a-b-a-b-c-c-d-d-e-d-E and a five-line envoi rhyming d-d-e-d-E.
The envoi first appears in the songs of the medieval trouvères and troubadours. Originally, they served as an address to the Prince (Puy) but they soon developed into addresses to the poet's beloved or to a friend or patron. As such, the envoi can be viewed as standing apart from the poem itself and expresses the poet's hope that the poem may bring them some benefit (the beloved's favours, increased patronage, and so on).
In the 14th century French poetry was tending to move away from song and towards written text. The two main forms used in this new literary poetry were the ballade, which employed a refrain at first but evolved to include an envoi and the chant royal, which used an envoi from the beginning.
The main exponents of these forms were Christine de Pizan and Charles d'Orléans. In the work of these poets, the nature of the envoi changed significantly. They occasionally retained the invocation of the Prince or to abstract entities such as Hope or Love as a cypher for an authority figure the protagonists(s) of the poem could appeal to, or, in the some poems by d'Orléans, to address actual royalty. However, more frequently in the works of these poets the envoi served as a commentary on the preceding stanzas, either reinforcing or ironically undercutting the message of the poem.
Jean Froissart, in his adaptation of the troubadour pastourelle genre to the chant royal form also employed the envoi. His use, however, is less innovative than that of de Pizan or d'Orléans. Froissart's envoi are invariably addressed to the Prince and are used to summarise the content of the preceding stanzas.
Since the 14th century, the envoi has been seen as an integral part of a number of traditional poetic forms, including, in addition to the ballade and chant royal, the virelai nouveau and the sestina. In English, poems with envoi have been written by poets as diverse as Austin Dobson, Algernon Charles Swinburne and Ezra Pound.