diff --git a/PersistentMail +CoreDataClass.swift b/PersistentMail +CoreDataClass.swift
index 8a1cc6a5e93af407d718940778d5d9090ca8a8c8..e5cc27f1c15c449a5456f2dd9ad35dfad462536a 100644
--- a/PersistentMail +CoreDataClass.swift	
+++ b/PersistentMail +CoreDataClass.swift	
@@ -91,7 +91,7 @@ open class PersistentMail: NSManagedObject, Mail {
         if message != nil {
             message = message!.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
             if message!.count > 50 {
-                message = message!.substring(to: message!.index(message!.startIndex, offsetBy: 50))
+                message = String(message![..<message!.index(message!.startIndex, offsetBy: 50)])
             }
             let messageArray = message!.components(separatedBy: "\n")
             return messageArray.joined(separator: " ")
diff --git a/enzevalos_iphone/ExportCells.swift b/enzevalos_iphone/ExportCells.swift
index 38114c7619765cbe34ab37887435cb9e3172c738..f7e12c3a9936001b56fb70d6179f466720711194 100644
--- a/enzevalos_iphone/ExportCells.swift
+++ b/enzevalos_iphone/ExportCells.swift
@@ -34,9 +34,9 @@ class ExportSecretCell: UITableViewCell {
         if secret.count == 44 {
             let cut1 = secret.index(secret.startIndex, offsetBy: 15)
             let cut2 = secret.index(secret.startIndex, offsetBy: 30)
-            secretRow1.text = secret.substring(to: cut1)
-            secretRow2.text = secret.substring(with: cut1..<cut2)
-            secretRow3.text = secret.substring(from: cut2)
+            secretRow1.text = String(secret[..<cut1])
+            secretRow2.text = String(secret[cut1..<cut2])
+            secretRow3.text = String(secret[cut2...])
         }
     }
     
diff --git a/enzevalos_iphone/Logger.swift b/enzevalos_iphone/Logger.swift
index 56b0e52ec17996e3214a5d35109f1bbe1290d490..d2aee80ecf9a6f6b5ca338470ddc5715ba90ad36 100644
--- a/enzevalos_iphone/Logger.swift
+++ b/enzevalos_iphone/Logger.swift
@@ -722,13 +722,13 @@ class Logger {
         while hasPrefix {
             if oldSubject.hasPrefix("Re: ") || oldSubject.hasPrefix("RE: ") || oldSubject.hasPrefix("re: ") || oldSubject.hasPrefix("AW: ") || oldSubject.hasPrefix("Aw: ") || oldSubject.hasPrefix("aw: ") {
                 newSubject += "Re: "
-                oldSubject = oldSubject.substring(from: oldSubject.index(oldSubject.startIndex, offsetBy: 4)) //damn swift3!
+                oldSubject = String(oldSubject[oldSubject.index(oldSubject.startIndex, offsetBy: 4)...]) //damn swift3!
             } else if oldSubject.hasPrefix("Fwd: ") || oldSubject.hasPrefix("FWD: ") || oldSubject.hasPrefix("fwd: ") {
                 newSubject += "Fwd: "
-                oldSubject = oldSubject.substring(from: oldSubject.index(oldSubject.startIndex, offsetBy: 5))
+                oldSubject = String(oldSubject[oldSubject.index(oldSubject.startIndex, offsetBy: 5)...])
             } else if oldSubject.hasPrefix("WG: ") || oldSubject.hasPrefix("Wg: ") || oldSubject.hasPrefix("wg: ") {
                 newSubject += "Fwd: "
-                oldSubject = oldSubject.substring(from: oldSubject.index(oldSubject.startIndex, offsetBy: 4))
+                oldSubject = String(oldSubject[oldSubject.index(oldSubject.startIndex, offsetBy: 4)...])
             } else {
                 hasPrefix = false
             }
diff --git a/enzevalos_iphone/MailHandler.swift b/enzevalos_iphone/MailHandler.swift
index 52f9f0864f5699fd4bac4deb8fc0bd6d17a45d56..a14e6e4cd02bc1b831a77c0aa5d792e6f1aa8b14 100644
--- a/enzevalos_iphone/MailHandler.swift
+++ b/enzevalos_iphone/MailHandler.swift
@@ -954,7 +954,7 @@ class MailHandler {
         if let lower = range?.lowerBound {
             range = text.range(of: "-----END PGP MESSAGE-----")
             if let upper = range?.upperBound {
-                let retValue = text.substring(to: upper).substring(from: lower)
+                let retValue = String(text[lower..<upper])
                 // We do not try to decrypt a previous mails.
                 if retValue.contains(">"){
                     return nil
diff --git a/enzevalos_iphone/PersistentMail +CoreDataProperties.swift b/enzevalos_iphone/PersistentMail +CoreDataProperties.swift
index 0d29eb8a1aeb2d6eea01dcc126ee65a534f0bf43..48336cc5db7b087696ecf6c091933bb4b3531e7b 100644
--- a/enzevalos_iphone/PersistentMail +CoreDataProperties.swift	
+++ b/enzevalos_iphone/PersistentMail +CoreDataProperties.swift	
@@ -171,7 +171,7 @@ extension PersistentMail {
         }
         if let key = keyword{
             if let range = (body.range(of: key)?.upperBound){
-                pw = body.substring(from: range)
+                pw = String(body[range...])
                 if let split = pw?.components(separatedBy: CharacterSet.whitespacesAndNewlines){
                     if split.count > 0 && split[0].count > 0{
                         pw = split[0]