Don't show incorrect mail address info on legacy plans

It is not true that legacy plans can have unlimited custom domains. Make
it not display anything here to prevent confusion.

Fixes #6540

src/misc/TranslationKey.ts

@@ -1625,6 +1625,7 @@ export type TranslationKeyType =
 	| "yourMessage_label"
 	| "you_label"
 	| "emptyString_msg"
+	| "mailAddressInfoLegacy_msg"
 	| "vcardInSharingFiles_msg"
 	| "importFromContactBook_label"
 	| "importContacts_label"

src/settings/mailaddress/MailAddressTable.ts

@@ -77,7 +77,7 @@ export class MailAddressTable implements Component<MailAddressTableAttrs> {
 								"{totalAmount}": model.aliasCount.totalAliases,
 							}),
 						),
-						m(".small.mt-s", lang.get("mailAddressInfo_msg")),
+						m(".small.mt-s", lang.get(model.aliasLimitIncludesCustomDomains() ? "mailAddressInfoLegacy_msg" : "mailAddressInfo_msg")),
 				  ]
 				: null,
 		]

src/settings/mailaddress/MailAddressTableModel.ts

@@ -43,10 +43,16 @@ export interface MailAddressNameChanger {
 /** Model for showing the list of mail addresses and optionally adding more, enabling/disabling/setting names for them. */
 export class MailAddressTableModel {
 	private nameMappings: AddressToName | null = null
+	private onLegacyPlan: boolean = false
 	aliasCount: MailAddressAliasServiceReturn | null = null
 
 	init: () => Promise<void> = lazyMemoized(async () => {
 		this.eventController.addEntityListener(this.entityEventsReceived)
+
+		// important: "not on legacy plan" is true for free plans
+		const userController = this.logins.getUserController()
+		this.onLegacyPlan = userController.isLegacyPlan(await userController.getPlanType())
+
 		await this.loadNames()
 		this.redraw()
 		await this.loadAliasCount()
@@ -72,6 +78,10 @@ export class MailAddressTableModel {
 		return this.logins.getUserController().isGlobalAdmin()
 	}
 
+	aliasLimitIncludesCustomDomains(): boolean {
+		return this.onLegacyPlan
+	}
+
 	addresses(): AddressInfo[] {
 		const { nameMappings } = this
 		if (nameMappings == null) {

src/translations/de.ts

@@ -1644,6 +1644,7 @@ export default {
 		"yourFolders_action": "DEINE ORDNER",
 		"yourMessage_label": "Deine Nachricht",
 		"you_label": "Du",
+		"mailAddressInfoLegacy_msg": "Deaktivierte E-Mail-Adressen können einer anderen Mailbox innerhalb deines Kontos zugewiesen werden.",
 		"vcardInSharingFiles_msg": "Wir haben eine oder mehrere Kontaktdateien entdeckt. Möchtest Du diese importieren oder anhängen?",
 		"importFromContactBook_label": "Kontakte von deinem Gerät importieren",
 		"importContacts_label": "Kontakte importieren"

src/translations/de_sie.ts

@@ -1644,6 +1644,7 @@ export default {
 		"yourFolders_action": "Ihre ORDNER",
 		"yourMessage_label": "Ihre Nachricht",
 		"you_label": "Sie",
+		"mailAddressInfoLegacy_msg": "Deaktivierte E-Mail-Adressen können einer anderen Mailbox innerhalb Ihres Kontos zugewiesen werden.",
 		"vcardInSharingFiles_msg": "Wir haben eine oder mehrere Kontaktdateien entdeckt. Möchten Sie diese importieren oder anhängen?",
 		"importFromContactBook_label": "Kontakte von Ihrem Gerät importieren",
 		"importContacts_label": "Kontakte importieren"

src/translations/en.ts

@@ -1640,6 +1640,7 @@ export default {
 		"yourFolders_action": "YOUR FOLDERS",
 		"yourMessage_label": "Your message",
 		"you_label": "You",
+		"mailAddressInfoLegacy_msg": "Disabled email addresses can be reassigned to another user or mailbox within your account.",
 		"vcardInSharingFiles_msg": "We detected one or more contact files, do you want to import or attach them?",
 		"importFromContactBook_label": "Import contacts from your device",
 		"importContacts_label": "Import contacts"