diff --git a/app/src/androidTest/kotlin/org/libremail/ui/onboarding/OnboardingFlowTest.kt b/app/src/androidTest/kotlin/org/libremail/ui/onboarding/OnboardingFlowTest.kt
index 121a218..ff116c8 100644
--- a/app/src/androidTest/kotlin/org/libremail/ui/onboarding/OnboardingFlowTest.kt
+++ b/app/src/androidTest/kotlin/org/libremail/ui/onboarding/OnboardingFlowTest.kt
@@ -254,10 +254,11 @@ class OnboardingFlowTest {
         waitForText("Yahoo Mail")
         composeTestRule.onNodeWithText("Yahoo Mail").performClick()
 
-        // Yahoo's setup screen keeps its app-password link…
+        // Yahoo's setup screen keeps its app-password link (now pointing at Yahoo's step-by-step
+        // instructions article instead of the generic account-security page, issue #155)…
         waitForText(string(R.string.app_password_open_page, "Yahoo Mail"))
         // …but gains no two-factor help link: unlike Gmail and iCloud, Yahoo gates nothing on it
-        // (issue #98, #153).
+        // (issue #98, #153, #155).
         composeTestRule.onNodeWithText(string(R.string.app_password_2fa_help)).assertDoesNotExist()
         composeTestRule.onNodeWithText(string(R.string.app_password_2fa_help_icloud)).assertDoesNotExist()
     }
diff --git a/app/src/main/kotlin/org/libremail/domain/model/MailProvider.kt b/app/src/main/kotlin/org/libremail/domain/model/MailProvider.kt
index 5f93cc2..1bfa541 100644
--- a/app/src/main/kotlin/org/libremail/domain/model/MailProvider.kt
+++ b/app/src/main/kotlin/org/libremail/domain/model/MailProvider.kt
@@ -64,7 +64,12 @@ enum class MailProvider(
     YAHOO(
         key = "yahoo",
         displayName = "Yahoo Mail",
-        appPasswordHelpUrl = "https://login.yahoo.com/account/security",
+        // Yahoo's own step-by-step "Generate and manage 3rd-party app passwords" article, not
+        // just the generic account-security sign-in page — that page assumes the user already
+        // knows to look for "Create app password" once there (issue #155). Unlike Gmail/iCloud,
+        // this article never lists two-step verification as a prerequisite for generating an app
+        // password, so there is no twoFactorHelpUrl below.
+        appPasswordHelpUrl = "https://my.help.yahoo.com/kb/mail/generate-app-specific-password-sln15241.html",
         imapHost = "imap.mail.yahoo.com",
         smtpHost = "smtp.mail.yahoo.com",
         // Yahoo documents smtp.mail.yahoo.com:465 with implicit SSL/TLS as its outgoing server.
diff --git a/app/src/main/kotlin/org/libremail/ui/compose/RichTextEditor.kt b/app/src/main/kotlin/org/libremail/ui/compose/RichTextEditor.kt
index 4f30d49..f97dae1 100644
--- a/app/src/main/kotlin/org/libremail/ui/compose/RichTextEditor.kt
+++ b/app/src/main/kotlin/org/libremail/ui/compose/RichTextEditor.kt
@@ -190,6 +190,13 @@ private fun FormattingToolbar(
             underline = true,
             onClick = { onToggleStyle(RichStyle.Underline) },
         )
+        FormatButton(
+            label = "S",
+            description = stringResource(R.string.format_strikethrough),
+            active = RichTextEditing.isStyled(content, start, end, RichStyle.Strikethrough),
+            strikethrough = true,
+            onClick = { onToggleStyle(RichStyle.Strikethrough) },
+        )
         FormatButton(
             label = "•",
             description = stringResource(R.string.format_bullet_list),
@@ -226,6 +233,7 @@ private fun FormatButton(
     fontWeight: FontWeight? = null,
     fontStyle: FontStyle? = null,
     underline: Boolean = false,
+    strikethrough: Boolean = false,
 ) {
     val colors = MaterialTheme.colorScheme
     val background = if (active) colors.secondaryContainer else Color.Transparent
@@ -244,7 +252,11 @@ private fun FormatButton(
             style = LocalTextStyle.current.copy(
                 fontWeight = fontWeight,
                 fontStyle = fontStyle,
-                textDecoration = if (underline) TextDecoration.Underline else null,
+                textDecoration = when {
+                    underline -> TextDecoration.Underline
+                    strikethrough -> TextDecoration.LineThrough
+                    else -> null
+                },
             ),
         )
     }
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0aec5ae..a8b8cb7 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -97,6 +97,7 @@
     <string name="format_bold">Bold</string>
     <string name="format_italic">Italic</string>
     <string name="format_underline">Underline</string>
+    <string name="format_strikethrough">Strikethrough</string>
     <string name="format_bullet_list">Bulleted list</string>
     <string name="format_numbered_list">Numbered list</string>
     <string name="format_quote">Block quote</string>
diff --git a/app/src/test/kotlin/org/libremail/domain/model/MailProviderTest.kt b/app/src/test/kotlin/org/libremail/domain/model/MailProviderTest.kt
index 69d16de..49f0ea1 100644
--- a/app/src/test/kotlin/org/libremail/domain/model/MailProviderTest.kt
+++ b/app/src/test/kotlin/org/libremail/domain/model/MailProviderTest.kt
@@ -96,7 +96,9 @@ class MailProviderTest {
         // generic Apple ID sign-in page (issue #153).
         assertEquals("https://support.apple.com/en-us/102660", MailProvider.ICLOUD.twoFactorHelpUrl)
 
-        // Yahoo gates nothing on two-factor, so it must not grow the extra link.
+        // Yahoo gates nothing on two-factor — reconfirmed directly against Yahoo's own help docs,
+        // which never list two-step verification as a prerequisite for generating an app password
+        // (issue #155) — so it must not grow the extra link.
         assertNull(MailProvider.YAHOO.twoFactorHelpUrl)
     }
 
@@ -105,6 +107,14 @@ class MailProviderTest {
         assertEquals("https://support.apple.com/en-us/102654", MailProvider.ICLOUD.appPasswordHelpUrl)
     }
 
+    @Test
+    fun `yahoo app-password help points at Yahoo's step-by-step instructions, not the generic sign-in page`() {
+        assertEquals(
+            "https://my.help.yahoo.com/kb/mail/generate-app-specific-password-sln15241.html",
+            MailProvider.YAHOO.appPasswordHelpUrl,
+        )
+    }
+
     @Test
     fun `createAccount trims the email and derives a stable id and display name`() {
         val account = MailProvider.GMAIL.createAccount("  User@Gmail.com  ")