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/settings/mailaddress/MailAddressTable.ts

@@ -17,7 +17,6 @@ import { AddressInfo, AddressStatus, MailAddressTableModel } from "./MailAddress
 import { showAddAliasDialog } from "./AddAliasDialog.js"
 import { locator } from "../../api/main/MainLocator.js"
 import { UpgradeRequiredError } from "../../api/main/UpgradeRequiredError.js"
-import { PlanType } from "../../api/common/TutanotaConstants.js"
 
 assertMainOrNode()
 
@@ -78,7 +77,7 @@ export class MailAddressTable implements Component<MailAddressTableAttrs> {
 								"{totalAmount}": model.aliasCount.totalAliases,
 							}),
 						),
-						m(".small.mt-s", lang.get("mailAddressInfo_msg")),
+						model.aliasLimitIncludesCustomDomains() ? m(".small.mt-s", lang.get("mailAddressInfo_msg")) : null,
 				  ]
 				: 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 notOnLegacyPlan: 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.notOnLegacyPlan = !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.notOnLegacyPlan
+	}
+
 	addresses(): AddressInfo[] {
 		const { nameMappings } = this
 		if (nameMappings == null) {