Ignatius of Antioch wrote c. 98-117 A.D., and only the collection of his writings, called the Middle Recension, is considered authentic. All others are forgeries. Still, one must remember that the topic of Ignatius’ letters’ authenticity is still much debated!
In his writings, Ignatius openly concedes that his teachings should not be considered commands for the church to follow, as if they are from an Apostle. Instead, he refers to himself as a “condemned man.” Perhaps that is the only wise admission Ignatius makes; both his Ecclesiology and view of Communion are novelties to what came before him.
Ecclesiology: In his view of Church governance, Ignatius was a first to posit loyalty to a single bishop. All others before him concluded a plurality of elders. In other words, Ignatius’ ecclesiology was without precedent, not in the Apostles (their writings) and not in the other direct disciples of the Apostles. As pointed out by Bart Ehrman, the strategic omissions of Antioch in Ignatius’ communications cast suspicion on Ignatius’ truly being Bishop of Antioch, as opposed to his declared title, Bishop of Syria. One wonders if Ignatius’ ways were too like Diotrephes for the Antiochian Christians (http://www.academia.edu/2043083/Ignatius_Redux_Bart_Ehrman_on_Ignatius_and_His_Letters_with_Brandon_Cline_, 444).
The Eucharist: if it is to be the body and blood of Jesus as Ignatius claims, then I remind the reader of Zwingli’s argument to Luther (see evidence below). Also, if Communion is “medicine for immortality,” as Ignatius asserts, then one bite of its infinitude should be sufficient; and if so, then why has not the entirety of the world eaten it willingly after seeing others before them brought substantively to the immortal state? No, no. As with anything, the reason a thing is done makes it holy as opposed to common. And, Jesus says, “do this in remembrance of me,” giving us the meaning, which sanctifies the elements to our minds and spirits. Communion is beneficial in that it is THE practice of unity of the saints, focusing our one love on our one Lord, as He bid us do until he Himself returns (which proves He is not then present).
Lastly, Ignatius goes to his martyrdom with a fixation on very gory and bloody details, which to me smacks of insanity and sacrilege to the concept of martyrdom.
THEREFORE, I do not trust Ignatius’ writings for establishing any norm of the early (post-Apostolic) Church, though his writings may be considered authentic and valuable only in that Ignatius liberally quotes the Gospels and attributes authority to the Apostles.
*“Ignatius of Antioch wrote in A.D. 117, “I do not, as Peter and Paul, issue commandments to you. They were apostles, I am but a condemned man.” (Laird Harris, Inspiration and Canonicity of the Bible (Grand Rapids, MI: Zondervan Publishing House, 1969), p. 237.)
*Five of these  letters are seemingly addressed to Christians in cities of the Roman province of Asia; the last one to the bishop of Smyrna. Several other recensions are also known, including the longer one with the initial seven letters greatly “updated” & embellished, plus an account (‘Martyrium Ignatii’) of Ignatius’ condemnation by Trajan himself in Antioch (Syria), trip to Rome & martyrdom there (with a post-mortem reappearance!). But all of them are considered spurious and written not before the 4th/5th century. More so because Eusebius, writing around 315, is totally unaware of those. However he named Ignatius & the seven letters, gave two quotes and some indication on their content (‘The History of the Church’ (HC), 3, 36). From the seven aforementioned letters –the commentaries of the fathers, up to Eusebius included, do not divulge much more– very few historical items appear about Ignatius: The seven letters are considered quasi-canonical by the Catholic Church (& some other ones) and the historical justification for many of its doctrines. One of the reasons would be Ignatius’ alleged acquaintance with Jesus’ disciples, as first “revealed” centuries later by bishops John Chrysostom (347-407) & Theodoret (393-457). (http://historical-jesus.info/ignatius.html, brackets mine).
*“Ignatius is the first known Christian writer to put great stress on loyality to a single bishop in each city, who is assisted by both presbyters (priests) and deacons. Earlier writings only mention either bishops or presbyters, and give the impression that there was usually more than one bishop per congregation. Ignatius also stresses the value of the Eucharist, calling it “a medicine to immortality”. The very strong desire for bloody martyrdom in the arena, which Ignatius expresses rather graphically in places, seems quite odd to the modern reader. (https://www.theopedia.com/ignatius-of-antioch, bold and underline mine)
*“Zwingli does seem to have some place for the notion of a spiritual feeding of Christ. Ultimately though, both he and Oecolampadius rejected Luther’s position at Marburg because they saw it as a threat to the validity of Christ’s resurrection and ascension – if Christ was physically resurrected in body, that body cannot be in two places at once (ie. at the right hand of the Father and in the bread/wine). To argue that it could, as Luther did, seemed to challenge the physical [and permanent] nature of Christ’s resurrection.” (https://www.theopedia.com/communion, brackets mine).
“So, not only did Calvin not accept what St. Ignatius taught in his epistles; he didn’t even accept them as genuine. So he can hardly have incorporated the data therein into his anti-Catholic apologetic. For him, the Ignatian corpus was entirely out of the equation of Protestant-Catholic disputation.” (http://www.patheos.com/blogs/davearmstrong/2016/08/john-calvin-ignatian-epistles-c-110-not-authentic.html#CCWrOTAr2mRY94OT.99)
Information on Ignatius of Antioch
William R. Schoedel comments on the recensions of Ignatius (The Anchor Bible Dictionary, v. 3, p. 384-385):
Eusebius (Hist. Eccl. 3.36) places Ignatius’ martyrdom in the reign of Trajan (A.D. 98-117), and a date in the second half of Trajan’s reign or somewhat later seems to fit the picture of the conditions reflected in the letters. Arguments are still advanced (notably by Joly 1979) that call into question the authenticity of these documents, but the researches of Zahn (1873) and Lightfoot (1885, 1889) and their followers continue to dominate the scholarship. Thus the authenticity of (a) what is not often, though misleadingly, called the “middle recension” is generally accepted. By the same token, (b) the so-called “long recension” is usually regarded as a 4th-century (perhaps Neo-Arrian) revision (Hagerdorn 1973: xxxvii-lii) consisting of interpolations into the original letters and the addition of 6 spurious letters. This recension is found in numerous Greek and Latin manuscripts and came to be the form in which Ignatius was most often known until Archbishop Ussher, in his Polycarpi et Ignatii Epistolae of 1644, brilliantly unearthed an earlier (Latin) form of the text akin to that quoted by Eusebius. Ussher had rediscovered the middle recension. The Greek of that recension (except for the letter to the Romans) became available with the publication of Igantius’ letters from Codex Mediceo-Laurentianus 57,7 by Isaak Voss in 1646. The Greek text of Ignatius’ letter to the Romans had a separate history as part of an account of Ignatius’ martyrdom (Codex Parisiensis-Colbertinus 1451), and this too was soon published by Th. Ruinart (1689). Our knowledge of the middle recension has been increased somewhat by the discovery of several important oriental versions: Coptic (fragments), Syriac (fragments), Armenian, Arabic. It should be noted that almost all of the collections of letters of the middle recension in the manuscripts also include some or all of the spurious letters. Since the interplations and the spurious letters are in all likelihood the work of one person, these collections represent a curious mixture of textual traditions. Finally, (c) what some have called the “short recension” proves to be no recension at all but merely an abridgment of a Syriac version of the middle recension. The term short recension, then, would serve most accurately to describe the so-called middle recension and is often so used. (http://www.earlychristianwritings.com/ignatius.html)