diff --git a/FlowCrypt/Controllers/Threads/ThreadDetailsViewController+TableView.swift b/FlowCrypt/Controllers/Threads/ThreadDetailsViewController+TableView.swift
index a8ea7e780..39b058a31 100644
--- a/FlowCrypt/Controllers/Threads/ThreadDetailsViewController+TableView.swift
+++ b/FlowCrypt/Controllers/Threads/ThreadDetailsViewController+TableView.swift
@@ -78,7 +78,12 @@ extension ThreadDetailsViewController: ASTableDelegate, ASTableDataSource {
             guard row > 1 + securityWarningBlockCount else {
                 if processedMessage.text.isHTMLString {
                     return ThreadDetailWebNode(
-                        input: .init(message: processedMessage.text, quote: processedMessage.quote, index: messageIndex)
+                        input: .init(
+                            message: processedMessage.text,
+                            quote: processedMessage.quote,
+                            index: messageIndex,
+                            isEncrypted: processedMessage.type == .encrypted
+                        )
                     )
                 }
                 return MessageTextSubjectNode(
diff --git a/FlowCryptCommon/Extensions/StringExtensions.swift b/FlowCryptCommon/Extensions/StringExtensions.swift
index 9b480ab69..d9b4977c0 100644
--- a/FlowCryptCommon/Extensions/StringExtensions.swift
+++ b/FlowCryptCommon/Extensions/StringExtensions.swift
@@ -93,15 +93,35 @@ public extension String {
             return "tag.fill"
         }
     }
-
+    
+    /// A regex that finds an opening HTML tag and captures its name.
+    private static let htmlTagRegex: NSRegularExpression? = {
+        try? NSRegularExpression(
+            pattern: "<([A-Za-z][A-Za-z0-9]*)\\b[^>]*>",
+            options: .caseInsensitive
+        )
+    }()
+  
+    /// Returns `true` if this string contains at least one full HTML element
+    /// (an opening `<tag…>` **and** a matching `</tag>`).
+    /// Email‑style `<…@…>` or other angle‑bracketed text won’t count.
     var isHTMLString: Bool {
-        do {
-            let regex = try NSRegularExpression(pattern: "<[a-z][\\s\\S]*>", options: .caseInsensitive)
-            let range = NSRange(startIndex..., in: self)
-            return regex.firstMatch(in: self, options: [], range: range) != nil
-        } catch {
-            return false
-        }
+       guard
+           let regex = Self.htmlTagRegex,
+           let match = regex.firstMatch(
+               in: self,
+               options: [],
+               range: NSRange(startIndex..<endIndex, in: self)
+           ),
+           match.numberOfRanges > 1,
+           let nameRange = Range(match.range(at: 1), in: self)
+       else {
+           return false
+       }
+
+       // Extract the tag name and look for its closing tag
+       let tagName = String(self[nameRange])
+       return range(of: "</\(tagName)>", options: .caseInsensitive) != nil
     }
 
     func removingHtmlTags() -> String {
diff --git a/FlowCryptUI/Cell Nodes/ThreadDetailWebNode.swift b/FlowCryptUI/Cell Nodes/ThreadDetailWebNode.swift
index a29a3747e..0b56d31fe 100644
--- a/FlowCryptUI/Cell Nodes/ThreadDetailWebNode.swift	
+++ b/FlowCryptUI/Cell Nodes/ThreadDetailWebNode.swift	
@@ -13,11 +13,13 @@ public final class ThreadDetailWebNode: CellNode {
         let message: String?
         let quote: String?
         let index: Int
+        let isEncrypted: Bool
 
-        public init(message: String?, quote: String?, index: Int) {
+        public init(message: String?, quote: String?, index: Int, isEncrypted: Bool) {
             self.message = message
             self.quote = quote
             self.index = index
+            self.isEncrypted = isEncrypted
         }
     }
 
@@ -50,7 +52,7 @@ public final class ThreadDetailWebNode: CellNode {
         self.input = input
 
         super.init()
-        addLeftBorder(width: .threadLeftBorderWidth, color: .plainTextBorder)
+        addLeftBorder(width: .threadLeftBorderWidth, color: input.isEncrypted ? .main : .plainTextBorder)
     }
 
     private func getFormattedHtml(html: String?) -> String {