diff --git a/REUSE.toml b/REUSE.toml
index 6925a14daf..e9e447c556 100644
--- a/REUSE.toml
+++ b/REUSE.toml
@@ -144,7 +144,7 @@ SPDX-FileCopyrightText = "2018-2024 Google LLC, 2016-2024 Nextcloud GmbH and Nex
 SPDX-License-Identifier = "Apache-2.0"
 
 [[annotations]]
-path = ["img/mail.png", "img/mail.svg", "img/mail-dark.svg", "img/important.svg", "img/star.png", "img/star.svg", "img/mail-notification.png", "img/mail-notification.svg", "img/text_snippet.svg", "img/format-pilcrow-arrow-right.svg", "img/format-pilcrow-arrow-left.svg"]
+path = ["img/mail.png", "img/mail.svg", "img/mail-dark.svg", "img/important.svg", "img/star.png", "img/star.svg", "img/mail-notification.png", "img/mail-notification.svg", "img/text_snippet.svg", "img/format-pilcrow-arrow-right.svg", "img/format-pilcrow-arrow-left.svg", "img/delegation.svg"]
 precedence = "aggregate"
 SPDX-FileCopyrightText = "2018-2026 Google LLC"
 SPDX-License-Identifier = "Apache-2.0"
diff --git a/img/delegation.svg b/img/delegation.svg
new file mode 100644
index 0000000000..dac6d654f5
--- /dev/null
+++ b/img/delegation.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 -960 960 960" width="24px" fill="#222222"><path d="M609-389q-29-29-29-71t29-71q29-29 71-29t71 29q29 29 29 71t-29 71q-29 29-71 29t-71-29ZM480-160v-56q0-24 12.5-44.5T528-290q36-15 74.5-22.5T680-320q39 0 77.5 7.5T832-290q23 9 35.5 29.5T880-216v56H480ZM287-527q-47-47-47-113t47-113q47-47 113-47t113 47q47 47 47 113t-47 113q-47 47-113 47t-113-47Zm113-113ZM80-160v-112q0-34 17-62.5t47-43.5q60-30 124.5-46T400-440q35 0 70 6t70 14l-34 34-34 34q-18-5-36-6.5t-36-1.5q-58 0-113.5 14T180-306q-10 5-15 14t-5 20v32h240v80H80Zm320-80Zm56.5-343.5Q480-607 480-640t-23.5-56.5Q433-720 400-720t-56.5 23.5Q320-673 320-640t23.5 56.5Q367-560 400-560t56.5-23.5Z"/></svg>
\ No newline at end of file
diff --git a/src/components/AppSettingsMenu.vue b/src/components/AppSettingsMenu.vue
index 62f64aea4b..c10fa694ff 100755
--- a/src/components/AppSettingsMenu.vue
+++ b/src/components/AppSettingsMenu.vue
@@ -32,6 +32,16 @@
 							</template>
 							{{ account.emailAddress }}
 						</NcFormBoxButton>
+						<NcFormBoxButton
+							v-for="account in delegatedAccounts"
+							:key="account.id"
+							:aria-label="t('mail', 'Account settings')"
+							@click="openAccountSettings(account.id)">
+							<template #icon>
+								<IconArrow :size="20" />
+							</template>
+							{{ t('mail', '{email} (delegated)', {email: account.emailAddress}) }}
+						</NcFormBoxButton>
 						<NcButton
 							v-if="allowNewMailAccounts"
 							variant="secondary"
@@ -409,7 +419,11 @@ export default {
 		},
 
 		accountsWithEmail() {
-			return this.getAccounts.filter((account) => account && account.emailAddress)
+			return this.getAccounts.filter((account) => account && account.emailAddress && !account.isDelegated)
+		},
+
+		delegatedAccounts() {
+			return this.getAccounts.filter((account) => account && account.emailAddress && account.isDelegated)
 		},
 
 		sortFavorites: {
diff --git a/src/components/DelegationModal.vue b/src/components/DelegationModal.vue
new file mode 100644
index 0000000000..cc27f09e26
--- /dev/null
+++ b/src/components/DelegationModal.vue
@@ -0,0 +1,315 @@
+<!--
+  - SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+  - SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+
+<template>
+	<NcModal v-if="view === 'main'" size="normal" @close="$emit('close')">
+		<div class="delegation-modal">
+			<h2>{{ t('mail', 'Delegation') }}</h2>
+
+			<div class="delegation-modal__section">
+				<p class="delegation-modal__description">
+					{{ t('mail', 'Allow users to send, receive, and delete mail on your behalf') }}
+				</p>
+
+				<NcListItem
+					v-for="user in delegates"
+					:key="user.userId"
+					:name="user.userId">
+					<template #icon>
+						<NcAvatar
+							disable-menu
+							:size="34"
+							:user="user.userId" />
+					</template>
+					<template #extra-actions>
+						<NcButton
+							:title="t('mail', 'Revoke access')"
+							:aria-label="t('mail', 'Revoke access')"
+							variant="tertiary-no-background"
+							@click="confirmRevoke(user)">
+							<template #icon>
+								<IconClose :size="20" />
+							</template>
+						</NcButton>
+					</template>
+				</NcListItem>
+
+				<NcButton
+					wide
+					variant="secondary"
+					@click="openAddDelegate">
+					<template #icon>
+						<IconPlus :size="20" />
+					</template>
+					{{ t('mail', 'Add delegate') }}
+				</NcButton>
+			</div>
+		</div>
+	</NcModal>
+
+	<NcDialog
+		v-else-if="view === 'add'"
+		class="add-delegates-dialog"
+		:open="view === 'add'"
+		:name="t('mail', 'Add delegate')"
+		:buttons="addDelegateButtons"
+		@closing="closeDialog">
+		<NcSelectUsers
+			v-model="selectedUser"
+			class="add-delegates-dialog__select"
+			:input-label="t('mail', 'Select a user')"
+			:options="userSuggestions"
+			:loading="searchLoading"
+			:placeholder="t('mail', 'Select a user')"
+			@search="onSearch" />
+		<p class="add-delegates-dialog__description">
+			{{ t('mail', 'They will be able to send, receive, and delete mail on your behalf') }}
+		</p>
+	</NcDialog>
+
+	<NcDialog
+		v-else-if="view === 'revoke'"
+		class="revoke-dialog"
+		:open="view === 'revoke'"
+		:name="t('mail', 'Revoke access?')"
+		:buttons="revokeButtons"
+		@closing="closeDialog">
+		<p class="revoke-dialog__text">
+			{{ revokeText }}
+		</p>
+	</NcDialog>
+</template>
+
+<script>
+import IconCheck from '@mdi/svg/svg/check.svg?raw'
+import { getCurrentUser } from '@nextcloud/auth'
+import axios from '@nextcloud/axios'
+import { showError, showSuccess } from '@nextcloud/dialogs'
+import { generateOcsUrl } from '@nextcloud/router'
+import { ShareType } from '@nextcloud/sharing'
+import { NcAvatar, NcButton, NcDialog, NcListItem, NcModal, NcSelectUsers } from '@nextcloud/vue'
+import debounce from 'lodash/fp/debounce.js'
+import IconClose from 'vue-material-design-icons/Close.vue'
+import IconPlus from 'vue-material-design-icons/Plus.vue'
+import logger from '../logger.js'
+import { delegate, fetchDelegatedUsers, unDelegate } from '../service/DelegationService.js'
+
+export default {
+	name: 'DelegationModal',
+	components: {
+		NcAvatar,
+		NcButton,
+		NcDialog,
+		NcListItem,
+		NcModal,
+		NcSelectUsers,
+		IconClose,
+		IconPlus,
+	},
+
+	props: {
+		account: {
+			type: Object,
+			required: true,
+		},
+	},
+
+	data() {
+		return {
+			view: 'main',
+			delegates: [],
+			revokeUser: null,
+			selectedUser: null,
+			userSuggestions: [],
+			searchLoading: false,
+			delegating: false,
+		}
+	},
+
+	computed: {
+		addDelegateButtons() {
+			return [
+				{
+					label: t('mail', 'Cancel'),
+					type: 'tertiary',
+					disabled: this.delegating,
+					callback: () => { this.closeDialog() },
+				},
+				{
+					label: t('mail', 'Delegate access'),
+					type: 'primary',
+					icon: IconCheck,
+					disabled: !this.selectedUser || this.delegating,
+					callback: () => { this.addDelegate() },
+				},
+			]
+		},
+
+		revokeButtons() {
+			return [
+				{
+					label: t('mail', 'Cancel'),
+					type: 'tertiary',
+					callback: () => { this.closeDialog() },
+				},
+				{
+					label: t('mail', 'Revoke'),
+					type: 'error',
+					callback: () => { this.revokeDelegate() },
+				},
+			]
+		},
+
+		revokeText() {
+			if (!this.revokeUser) {
+				return ''
+			}
+			return t('mail', '{userId} will no longer be able to act on your behalf', { userId: this.revokeUser.userId })
+		},
+	},
+
+	async mounted() {
+		await this.fetchDelegates()
+	},
+
+	methods: {
+		async fetchDelegates() {
+			try {
+				this.delegates = await fetchDelegatedUsers(this.account.accountId)
+			} catch (error) {
+				logger.error('Could not fetch delegates', { error })
+				showError(t('mail', 'Could not fetch delegates'))
+			}
+		},
+
+		openAddDelegate() {
+			this.view = 'add'
+		},
+
+		confirmRevoke(user) {
+			this.revokeUser = user
+			this.view = 'revoke'
+		},
+
+		onSearch(query) {
+			this.debounceGetSuggestions(query.trim())
+		},
+
+		debounceGetSuggestions: debounce(300, function(...args) {
+			this.getSuggestions(...args)
+		}),
+
+		async getSuggestions(search) {
+			if (!search) {
+				this.userSuggestions = []
+				return
+			}
+
+			this.searchLoading = true
+			try {
+				const request = await axios.get(generateOcsUrl('apps/files_sharing/api/v1/sharees'), {
+					params: {
+						format: 'json',
+						itemType: 'file',
+						search,
+						shareTypes: [ShareType.User],
+					},
+				})
+
+				const data = request.data.ocs.data
+				const exact = request.data.ocs.data.exact
+
+				const rawSuggestions = exact.users.concat(data.users)
+				const currentUserId = getCurrentUser().uid
+				const delegateIds = this.delegates.map((d) => d.userId)
+
+				this.userSuggestions = rawSuggestions
+					.map((result) => ({
+						id: result.value.shareWith,
+						displayName: result.name || result.label,
+						subname: result.value.shareWith,
+						user: result.value.shareWith,
+					}))
+					.filter((u) => u.id !== currentUserId && !delegateIds.includes(u.id))
+			} catch (error) {
+				logger.error('Error fetching user suggestions', { error })
+			} finally {
+				this.searchLoading = false
+			}
+		},
+
+		async addDelegate() {
+			if (!this.selectedUser) {
+				return
+			}
+
+			this.delegating = true
+			try {
+				const delegation = await delegate(this.account.accountId, this.selectedUser.id)
+				this.delegates.push(delegation)
+				showSuccess(t('mail', 'Delegated access to {userId}', { userId: this.selectedUser.id }))
+				this.delegating = false
+			} catch (error) {
+				logger.error('Could not delegate access', { error })
+				showError(t('mail', 'Could not delegate access'))
+				this.delegating = false
+			}
+		},
+
+		async revokeDelegate() {
+			if (!this.revokeUser) {
+				return
+			}
+
+			try {
+				await unDelegate(this.account.accountId, this.revokeUser.userId)
+				this.delegates = this.delegates.filter((d) => d.userId !== this.revokeUser.userId)
+				showSuccess(t('mail', 'Revoked access for {userId}', { userId: this.revokeUser.userId }))
+			} catch (error) {
+				logger.error('Could not revoke delegation', { error })
+				showError(t('mail', 'Could not revoke delegation'))
+			}
+		},
+
+		closeDialog() {
+			this.view = 'main'
+		},
+	},
+}
+</script>
+
+<style lang="scss" scoped>
+.delegation-modal {
+	padding: var(--default-grid-baseline) calc(var(--default-grid-baseline) * 3) calc(var(--default-grid-baseline) * 3);
+	h2 {
+		margin: 0;
+		text-align: center;
+	}
+	&__section {
+		margin-top: calc(var(--default-grid-baseline) * 3);
+	}
+
+	&__description {
+		color: var(--color-text-maxcontrast);
+		margin-bottom: calc(var(--default-grid-baseline) * 2);
+	}
+}
+
+.add-delegates-dialog{
+	&__description{
+		color: var(--color-text-maxcontrast);
+		padding: calc(var(--default-grid-baseline) * 2) 0;
+	}
+	&__select{
+		width: 100%;
+	}
+}
+
+.revoke-dialog {
+	&__text{
+		padding-bottom: calc(var(--default-grid-baseline) * 2);
+	}
+}
+</style>
diff --git a/src/components/NavigationAccount.vue b/src/components/NavigationAccount.vue
index 797ec33081..3cc520a4ee 100644
--- a/src/components/NavigationAccount.vue
+++ b/src/components/NavigationAccount.vue
@@ -36,6 +36,18 @@
 						</template>
 						{{ t('mail', 'Account settings') }}
 					</ActionButton>
+					<ActionButton
+						v-if="canDelegate"
+						:close-after-click="true"
+						@click="showDelegationModal = true">
+						<template #icon>
+							<NcIconSvgWrapper
+								:size="20"
+								:title="t('mail', 'Delegate account')"
+								:svg="IconDelegation" />
+						</template>
+						{{ t('mail', 'Delegate account') }}
+					</ActionButton>
 					<ActionCheckbox
 						:checked="account.showSubscribedOnly"
 						:disabled="savingShowOnlySubscribed"
@@ -85,6 +97,7 @@
 			</template>
 		</NcAppNavigationCaption>
 		<AccountSettings :open="showSettings" :account="account" @update:open="showAccountSettings($event)" />
+		<DelegationModal v-if="showDelegationModal" :account="account" @close="showDelegationModal = false" />
 	</Fragment>
 </template>
 
@@ -92,7 +105,7 @@
 import { DialogBuilder, showError } from '@nextcloud/dialogs'
 import { formatFileSize } from '@nextcloud/files'
 import { generateUrl } from '@nextcloud/router'
-import { NcActionButton as ActionButton, NcActionCheckbox as ActionCheckbox, NcActionInput as ActionInput, NcActionText as ActionText, NcLoadingIcon as IconLoading, NcAppNavigationCaption } from '@nextcloud/vue'
+import { NcActionButton as ActionButton, NcActionCheckbox as ActionCheckbox, NcActionInput as ActionInput, NcActionText as ActionText, NcLoadingIcon as IconLoading, NcAppNavigationCaption, NcIconSvgWrapper } from '@nextcloud/vue'
 import { mapStores } from 'pinia'
 import { Fragment } from 'vue-frag'
 import MenuDown from 'vue-material-design-icons/ChevronDown.vue'
@@ -104,6 +117,7 @@ import IconDelete from 'vue-material-design-icons/TrashCanOutline.vue'
 import logger from '../logger.js'
 import { fetchQuota } from '../service/AccountService.js'
 import useMainStore from '../store/mainStore.js'
+import IconDelegation from './../../img/delegation.svg'
 
 export default {
 	name: 'NavigationAccount',
@@ -115,8 +129,10 @@ export default {
 		ActionInput,
 		ActionText,
 		AccountSettings: () => import(/* webpackChunkName: "account-settings" */ './AccountSettings.vue'),
+		DelegationModal: () => import(/* webpackChunkName: "delegation-modal" */ './DelegationModal.vue'),
 		IconInfo,
 		IconSettings,
+		NcIconSvgWrapper,
 		IconFolderAdd,
 		MenuDown,
 		MenuUp,
@@ -162,6 +178,8 @@ export default {
 			quota: undefined,
 			editing: false,
 			showSaving: false,
+			showDelegationModal: false,
+			IconDelegation,
 			createMailboxName: '',
 			showMailboxes: false,
 			nameInput: false,
@@ -179,6 +197,10 @@ export default {
 			return this.account.isUnified !== true && this.account.visible !== false
 		},
 
+		canDelegate() {
+			return !this.account.isDelegated
+		},
+
 		id() {
 			return 'account-' + this.account.id
 		},
diff --git a/src/service/DelegationService.js b/src/service/DelegationService.js
new file mode 100644
index 0000000000..379ab86c79
--- /dev/null
+++ b/src/service/DelegationService.js
@@ -0,0 +1,58 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+import axios from '@nextcloud/axios'
+import { generateUrl } from '@nextcloud/router'
+
+/**
+ * @typedef Delegation
+ * @property {number} id the delegation id
+ * @property {number} accountId the account id
+ * @property {string} userId the delegated user id
+ */
+
+/**
+ * Fetch all users that have delegation for a given account
+ *
+ * @param {number} accountId id of the account
+ * @return {Promise<Delegation[]>}
+ */
+export async function fetchDelegatedUsers(accountId) {
+	const url = generateUrl('/apps/mail/api/delegations/{accountId}', {
+		accountId,
+	})
+
+	return axios.get(url).then((resp) => resp.data)
+}
+
+/**
+ * Delegate an account to a user
+ *
+ * @param {number} accountId id of the account
+ * @param {string} userId id of the user to delegate to
+ * @return {Promise<Delegation>}
+ */
+export async function delegate(accountId, userId) {
+	const url = generateUrl('/apps/mail/api/delegations/{accountId}', {
+		accountId,
+	})
+
+	return axios.post(url, { userId }).then((resp) => resp.data)
+}
+
+/**
+ * Revoke delegation of an account for a user
+ *
+ * @param {number} accountId id of the account
+ * @param {string} userId id of the user to revoke delegation for
+ * @return {Promise}
+ */
+export async function unDelegate(accountId, userId) {
+	const url = generateUrl('/apps/mail/api/delegations/{accountId}/{userId}', {
+		accountId,
+		userId,
+	})
+
+	return axios.delete(url).then((resp) => resp.data)
+}