diff --git a/src/components/MultiStepForm.tsx b/src/components/MultiStepForm.tsx
index bf7f49d..ffcd3ca 100644
--- a/src/components/MultiStepForm.tsx
+++ b/src/components/MultiStepForm.tsx
@@ -26,15 +26,20 @@ function MultiStepForm({
 	const [currentSize, setCurrentSize] = useState<any>(null)
 	const [nextSize, setNextSize] = useState<any>(null)
 
-	const isTransitioning = currentIndex !== index
+	const isTransitioning = currentIndex < index
 
 	useEffect(() => {
-		if (index !== currentIndex) {
+		if (index > currentIndex) {
 			$timeout.current = setTimeout(() => {
 				setCurrentSize(null)
 				setNextSize(null)
 				setCurrentIndex(index)
 			}, duration)
+		} else if (index < currentIndex) {
+			// "Going-back" animation is not supported
+			setCurrentIndex(index)
+			setCurrentSize(null)
+			setNextSize(null)
 		}
 
 		return $timeout.current?.cancel!
diff --git a/src/components/OpenMailButton.tsx b/src/components/OpenMailButton.tsx
index 41b24e2..6d37bf2 100644
--- a/src/components/OpenMailButton.tsx
+++ b/src/components/OpenMailButton.tsx
@@ -19,7 +19,7 @@ export default function OpenMailButton({
 		return (
 			<Button
 				startIcon={<IoMdMailOpen />}
-				variant="contained"
+				variant="text"
 				href={APP_LINK_MAP[domain].android}
 			>
 				Open Mail
diff --git a/src/route-widgets/root/EmailForm/EmailForm.tsx b/src/route-widgets/root/EmailForm/EmailForm.tsx
index b36dbdb..da0e815 100644
--- a/src/route-widgets/root/EmailForm/EmailForm.tsx
+++ b/src/route-widgets/root/EmailForm/EmailForm.tsx
@@ -1,37 +1,66 @@
+import * as yup from "yup"
 import {useFormik} from "formik"
 import {MdEmail} from "react-icons/md"
+import {AxiosError} from "axios"
 import React, {ReactElement} from "react"
 
 import {InputAdornment, TextField} from "@mui/material"
 
 import {MultiStepFormElement, SimpleForm} from "~/components"
-import {signup} from "~/apis"
-import {handleErrors} from "~/utils"
-import {ServerSettings} from "~/types"
+import {checkIsDomainDisposable, signup} from "~/apis"
+import {parseFastapiError} from "~/utils"
+import {ServerSettings} from "~/server-types"
 
 import DetectEmailAutofillService from "./DetectEmailAutofillService"
-import useSchema, {Form} from "./use-schema"
 
-interface EmailFormProps {
+export interface EmailFormProps {
 	serverSettings: ServerSettings
 	onSignUp: (email: string) => void
 }
 
+interface Form {
+	email: string
+	detail?: string
+}
+
+const SCHEMA = yup.object().shape({
+	email: yup.string().email().required(),
+})
+
 export default function EmailForm({
 	onSignUp,
 	serverSettings,
 }: EmailFormProps): ReactElement {
-	const schema = useSchema(serverSettings)
 	const formik = useFormik<Form>({
-		validationSchema: schema,
+		validationSchema: SCHEMA,
 		initialValues: {
 			email: "",
 		},
-		onSubmit: (values, {setErrors}) =>
-			handleErrors(
-				values.email,
-				setErrors,
-			)(signup).then(({normalized_email}) => onSignUp(normalized_email)),
+		onSubmit: async (values, {setErrors}) => {
+			// Check is email disposable
+			try {
+				const isDisposable = await checkIsDomainDisposable(values.email)
+
+				if (isDisposable) {
+					setErrors({
+						email: "Disposable email addresses are not allowed",
+					})
+					return
+				}
+			} catch {
+				setErrors({
+					detail: "An error occurred",
+				})
+				return
+			}
+
+			try {
+				await signup(values.email)
+				onSignUp(values.email)
+			} catch (error) {
+				setErrors(parseFastapiError(error as AxiosError))
+			}
+		},
 	})
 
 	return (
diff --git a/src/route-widgets/root/EmailForm/use-schema.ts b/src/route-widgets/root/EmailForm/use-schema.ts
deleted file mode 100644
index 09e22dc..0000000
--- a/src/route-widgets/root/EmailForm/use-schema.ts
+++ /dev/null
@@ -1,44 +0,0 @@
-import * as yup from "yup"
-
-import {checkIsDomainDisposable} from "~/apis"
-import {ServerSettings} from "~/types"
-
-export interface Form {
-	email: string
-	detail?: string
-}
-
-export default function useSchema(
-	serverSettings: ServerSettings,
-): yup.BaseSchema {
-	return yup.object().shape({
-		email: yup
-			.string()
-			.email()
-			.required()
-			.test(
-				"notDisposable",
-				"Disposable email addresses are not allowed",
-				async (value, context) => {
-					if (serverSettings.disposable_emails_enabled) {
-						return true
-					}
-
-					try {
-						await yup.string().email().validate(value, {
-							strict: true,
-						})
-						const isDisposable = await checkIsDomainDisposable(
-							value!.split("@")[1],
-						)
-
-						return !isDisposable
-					} catch ({message}) {
-						// @ts-ignore
-						context.createError({message})
-						return false
-					}
-				},
-			),
-	})
-}
diff --git a/src/route-widgets/root/PasswordForm.tsx b/src/route-widgets/root/PasswordForm.tsx
index 1b914a5..d1dccae 100644
--- a/src/route-widgets/root/PasswordForm.tsx
+++ b/src/route-widgets/root/PasswordForm.tsx
@@ -8,7 +8,7 @@ import {LoadingButton} from "@mui/lab"
 import {Box, Grid, InputAdornment, Typography} from "@mui/material"
 
 import {PasswordField} from "~/components"
-import {encryptString, handleErrors} from "~/utils"
+import {encryptString} from "~/utils"
 import {isDev} from "~/constants/development"
 
 export interface PasswordFormProps {
@@ -18,6 +18,7 @@ export interface PasswordFormProps {
 interface Form {
 	password: string
 	passwordConfirmation: string
+	detail?: string
 }
 
 const schema = yup.object().shape({
@@ -47,11 +48,8 @@ export default function PasswordForm({email}: PasswordFormProps): ReactElement {
 			password: "",
 			passwordConfirmation: "",
 		},
-		onSubmit: (values, {setErrors}) =>
-			handleErrors(
-				values,
-				setErrors,
-			)(async () => {
+		onSubmit: async (values, {setErrors}) => {
+			try {
 				const keyPair = await awaitGenerateKey
 
 				const encryptedPrivateKey = encryptString(
@@ -60,7 +58,10 @@ export default function PasswordForm({email}: PasswordFormProps): ReactElement {
 				)
 
 				console.log(encryptedPrivateKey)
-			}),
+			} catch (error) {
+				setErrors({detail: "An error occurred"})
+			}
+		},
 	})
 
 	return (
diff --git a/src/route-widgets/root/YouGotMail/YouGotMail.tsx b/src/route-widgets/root/YouGotMail/YouGotMail.tsx
index d2c8729..2308b45 100644
--- a/src/route-widgets/root/YouGotMail/YouGotMail.tsx
+++ b/src/route-widgets/root/YouGotMail/YouGotMail.tsx
@@ -1,47 +1,103 @@
-import React, {ReactElement} from "react"
+import {MdCancel, MdEdit} from "react-icons/md"
+import React, {ReactElement, useState} from "react"
 
-import {Grid, Typography} from "@mui/material"
+import {
+	Button,
+	Dialog,
+	DialogActions,
+	DialogContent,
+	DialogContentText,
+	DialogTitle,
+	Grid,
+	IconButton,
+	Typography,
+} from "@mui/material"
 
 import {MultiStepFormElement, OpenMailButton} from "~/components"
 import ResendMailButton from "~/route-widgets/root/YouGotMail/ResendMailButton"
 
 export interface YouGotMailProps {
 	email: string
+	onGoBack: () => void
 }
 
-export default function YouGotMail({email}: YouGotMailProps): ReactElement {
+export default function YouGotMail({
+	email,
+	onGoBack,
+}: YouGotMailProps): ReactElement {
+	const [askToEditEmail, setAskToEditEmail] = useState<boolean>(false)
+
 	const domain = email.split("@")[1]
 
 	return (
-		<MultiStepFormElement>
-			<Grid
-				container
-				direction="column"
-				spacing={4}
-				paddingX={2}
-				paddingY={4}
-				alignItems="center"
-				justifyContent="center"
-			>
-				<Grid item>
-					<Typography variant="h6" component="h2" align="center">
-						You got mail!
-					</Typography>
+		<>
+			<MultiStepFormElement>
+				<Grid
+					container
+					direction="column"
+					spacing={4}
+					paddingX={2}
+					paddingY={4}
+					alignItems="center"
+					justifyContent="center"
+				>
+					<Grid item>
+						<Typography variant="h6" component="h2" align="center">
+							You got mail!
+						</Typography>
+					</Grid>
+					<Grid item>
+						<Typography variant="subtitle1" component="p">
+							We sent you an email with a link to confirm your
+							email address. Please check your inbox and click on
+							the link to continue.
+						</Typography>
+					</Grid>
+					<Grid item>
+						<Grid
+							container
+							alignItems="center"
+							direction="row"
+							spacing={2}
+						>
+							<Grid item>
+								<code>{email}</code>
+							</Grid>
+							<Grid item>
+								<IconButton
+									onClick={() => setAskToEditEmail(true)}
+								>
+									<MdEdit />
+								</IconButton>
+							</Grid>
+						</Grid>
+					</Grid>
+					<Grid item>
+						<OpenMailButton domain={domain} />
+					</Grid>
+					<Grid item>
+						<ResendMailButton email={email} />
+					</Grid>
 				</Grid>
-				<Grid item>
-					<Typography variant="subtitle1" component="p">
-						We sent you an email with a link to confirm your email
-						address. Please check your inbox and click on the link
-						to continue.
-					</Typography>
-				</Grid>
-				<Grid item>
-					<OpenMailButton domain={domain} />
-				</Grid>
-				<Grid item>
-					<ResendMailButton email={email} />
-				</Grid>
-			</Grid>
-		</MultiStepFormElement>
+			</MultiStepFormElement>
+			<Dialog open={askToEditEmail}>
+				<DialogTitle>Edit email address?</DialogTitle>
+				<DialogContent>
+					<DialogContentText>
+						Would you like to return to the previous step and edit
+						your email address?
+					</DialogContentText>
+				</DialogContent>
+				<DialogActions>
+					<Button
+						startIcon={<MdCancel />}
+						onClick={() => setAskToEditEmail(false)}
+					>
+						Cancel
+					</Button>
+					<Button onClick={onGoBack}>Yes, edit email</Button>
+				</DialogActions>
+			</Dialog>
+		</>
 	)
 }
diff --git a/src/routes/SignupRoute.tsx b/src/routes/SignupRoute.tsx
index 17ef45a..102f64c 100644
--- a/src/routes/SignupRoute.tsx
+++ b/src/routes/SignupRoute.tsx
@@ -3,7 +3,7 @@ import {useLocalStorage} from "react-use"
 import {useLoaderData} from "react-router-dom"
 
 import {MultiStepForm} from "~/components"
-import {ServerSettings} from "~/types"
+import {ServerSettings} from "~/server-types"
 import EmailForm from "~/route-widgets/root/EmailForm"
 import YouGotMail from "~/route-widgets/root/YouGotMail"
 
@@ -24,7 +24,11 @@ export default function SignupRoute(): ReactElement {
 					onSignUp={setEmail}
 					key="email"
 				/>,
-				<YouGotMail email={email || ""} key="you_got_mail" />,
+				<YouGotMail
+					onGoBack={() => setEmail("")}
+					email={email || ""}
+					key="you_got_mail"
+				/>,
 			]}
 			index={index}
 		/>
diff --git a/src/routes/VerifyEmailRoute.tsx b/src/routes/VerifyEmailRoute.tsx
index 093e6ad..05323b5 100644
--- a/src/routes/VerifyEmailRoute.tsx
+++ b/src/routes/VerifyEmailRoute.tsx
@@ -6,7 +6,7 @@ import React, {ReactElement} from "react"
 
 import {Grid, Paper, Typography, useTheme} from "@mui/material"
 
-import {ServerSettings} from "~/types"
+import {ServerSettings} from "~/server-types"
 import {validateEmail} from "~/apis"
 
 const emailSchema = yup.string().email()
diff --git a/src/utils/handle-errors.ts b/src/utils/handle-errors.ts
deleted file mode 100644
index bd730d8..0000000
--- a/src/utils/handle-errors.ts
+++ /dev/null
@@ -1,17 +0,0 @@
-import {FormikHelpers} from "formik"
-import parseFastAPIError from "./parse-fastapi-error"
-import {AxiosError} from "axios"
-
-export default function handleErrors<T = any, Result = any, Values = any>(
-	values: T,
-	setErrors: FormikHelpers<Values>["setErrors"],
-) {
-	return async (callback: (values: T) => Promise<Result>) => {
-		try {
-			const result = await callback(values)
-			return result
-		} catch (error) {
-			setErrors(parseFastAPIError(error as AxiosError))
-		}
-	}
-}
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 53da680..9bbea87 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -1,9 +1,7 @@
 export * from "./app-url-links"
 export {default as APP_LINK_MAP} from "./app-url-links"
 export * from "./encrypt-string"
-export { default as encryptString } from "./encrypt-string"
-export * from "./handle-errors"
-export {default as handleErrors} from "./handle-errors"
+export {default as encryptString} from "./encrypt-string"
 export * from "./parse-fastapi-error"
 export {default as parseFastapiError} from "./parse-fastapi-error"
 export * from "./when-element-has-bounds"