diff --git a/CHANGELOG.md b/CHANGELOG.md
index bda7041ee..7c76c83e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,9 +3,12 @@
 
 -------------------------------------------------------------------------------------------------------------
 
-# 5.7.16 (2021-10-21)
+# 5.7.16 (2021-10-23)
 
 ### 🐣新特性
+* 【core   】     增加DateTime.toLocalDateTime
+* 【core   】     CharSequenceUtil增加normalize方法（pr#444@Gitee）
+* 【core   】     MailAccount增加setEncodefilename()方法，可选是否编码附件的文件名（issue#I4F160@Gitee）
 
 ### 🐞Bug修复
 
diff --git a/hutool-core/src/main/java/cn/hutool/core/date/DateTime.java b/hutool-core/src/main/java/cn/hutool/core/date/DateTime.java
index 6758c3768..d577399a7 100644
--- a/hutool-core/src/main/java/cn/hutool/core/date/DateTime.java
+++ b/hutool-core/src/main/java/cn/hutool/core/date/DateTime.java
@@ -12,6 +12,7 @@ import java.sql.Timestamp;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.time.Instant;
+import java.time.LocalDateTime;
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
@@ -701,6 +702,16 @@ public class DateTime extends Date {
 		return new java.sql.Date(getTime());
 	}
 
+	/**
+	 * 转换为 {@link LocalDateTime}
+	 *
+	 * @return {@link LocalDateTime}
+	 * @since 5.7.16
+	 */
+	public LocalDateTime toLocalDateTime() {
+		return LocalDateTimeUtil.of(this);
+	}
+
 	/**
 	 * 计算相差时长
 	 *
diff --git a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
index 1a41d7282..6ca7f6c32 100644
--- a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
@@ -18,6 +18,7 @@ import cn.hutool.core.util.StrUtil;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.text.MessageFormat;
+import java.text.Normalizer;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.LinkedList;
@@ -4338,7 +4339,21 @@ public class CharSequenceUtil {
 	 * @return 给定字符串的所有字符是否都一样
 	 * @since 5.7.3
 	 */
-	public static boolean isCharEquals(String str) {
-		return isBlank(str.replace(str.charAt(0), CharUtil.SPACE));
+	public static boolean isCharEquals(CharSequence str) {
+		Assert.notEmpty(str, "Str to check must be not empty!");
+		return count(str, str.charAt(0)) == str.length();
+	}
+
+	/**
+	 * 对字符串归一化处理，如 "Á" 可以使用 "u00C1"或 "u0041u0301"表示，实际测试中两个字符串并不equals<br>
+	 * 因此使用此方法归一为一种表示形式，默认按照W3C通常建议的，在NFC中交换文本。
+	 *
+	 * @param str 归一化的字符串
+	 * @return 归一化后的字符串
+	 * @see Normalizer#normalize(CharSequence, Normalizer.Form)
+	 * @since 5.7.16
+	 */
+	public static String normalize(CharSequence str) {
+		return Normalizer.normalize(str, Normalizer.Form.NFC);
 	}
 }
diff --git a/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java
index bec53ad4d..85a35a18c 100644
--- a/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/text/CharSequenceUtilTest.java
@@ -33,5 +33,19 @@ public class CharSequenceUtilTest {
 		Assert.assertEquals( str + " is Good", result);
 	}
 
+	@Test
+	public void normalizeTest(){
+		// https://blog.csdn.net/oscar999/article/details/105326270
+
+		String str1 = "\u00C1";
+		String str2 = "\u0041\u0301";
+
+		Assert.assertNotEquals(str1, str2);
+
+		str1 = CharSequenceUtil.normalize(str1);
+		str2 = CharSequenceUtil.normalize(str2);
+		Assert.assertEquals(str1, str2);
+	}
+
 	// ------------------------------------------------------------------------ remove
 }
diff --git a/hutool-extra/src/main/java/cn/hutool/extra/mail/Mail.java b/hutool-extra/src/main/java/cn/hutool/extra/mail/Mail.java
index 1f28d16a9..e4ce322c9 100644
--- a/hutool-extra/src/main/java/cn/hutool/extra/mail/Mail.java
+++ b/hutool-extra/src/main/java/cn/hutool/extra/mail/Mail.java
@@ -36,6 +36,7 @@ import java.util.Date;
  * @since 3.2.0
  */
 public class Mail implements Builder<MimeMessage> {
+	private static final long serialVersionUID = 1L;
 
 	/**
 	 * 邮箱帐户信息以及一些客户端配置信息
@@ -262,7 +263,10 @@ public class Mail implements Builder<MimeMessage> {
 				for (DataSource attachment : attachments) {
 					bodyPart = new MimeBodyPart();
 					bodyPart.setDataHandler(new DataHandler(attachment));
-					nameEncoded = InternalMailUtil.encodeText(attachment.getName(), charset);
+					nameEncoded = attachment.getName();
+					if(this.mailAccount.isEncodefilename()){
+						nameEncoded = InternalMailUtil.encodeText(nameEncoded, charset);
+					}
 					// 普通附件文件名
 					bodyPart.setFileName(nameEncoded);
 					if (StrUtil.startWith(attachment.getContentType(), "image/")) {
diff --git a/hutool-extra/src/main/java/cn/hutool/extra/mail/MailAccount.java b/hutool-extra/src/main/java/cn/hutool/extra/mail/MailAccount.java
index 925550241..8ea8aed62 100644
--- a/hutool-extra/src/main/java/cn/hutool/extra/mail/MailAccount.java
+++ b/hutool-extra/src/main/java/cn/hutool/extra/mail/MailAccount.java
@@ -34,8 +34,10 @@ public class MailAccount implements Serializable {
 	private static final String SOCKET_FACTORY_FALLBACK = "mail.smtp.socketFactory.fallback";
 	private static final String SOCKET_FACTORY_PORT = "smtp.socketFactory.port";
 
+	// 其他
 	private static final String MAIL_DEBUG = "mail.debug";
 	private static final String SPLIT_LONG_PARAMS = "mail.mime.splitlongparameters";
+	// private static final String ENCODE_FILE_NAME = "mail.mime.encodefilename";
 
 	public static final String[] MAIL_SETTING_PATHS = new String[]{"config/mail.setting", "config/mailAccount.setting", "mail.setting"};
 
@@ -75,7 +77,11 @@ public class MailAccount implements Serializable {
 	/**
 	 * 对于超长参数是否切分为多份，默认为false（国内邮箱附件不支持切分的附件名）
 	 */
-	private boolean splitlongparameters;
+	private boolean splitlongparameters = false;
+	/**
+	 * 对于文件名是否使用{@link #charset}编码，默认为 {@code true}
+	 */
+	private boolean encodefilename = true;
 
 	/**
 	 * 使用 STARTTLS安全连接，STARTTLS是对纯文本通信协议的扩展。它将纯文本连接升级为加密连接（TLS或SSL）， 而不是使用一个单独的加密通信端口。
@@ -332,6 +338,26 @@ public class MailAccount implements Serializable {
 		this.splitlongparameters = splitlongparameters;
 	}
 
+	/**
+	 * 对于文件名是否使用{@link #charset}编码，默认为 {@code true}
+	 *
+	 * @return 对于文件名是否使用{@link #charset}编码，默认为 {@code true}
+	 * @since 5.7.16
+	 */
+	public boolean isEncodefilename() {
+		return encodefilename;
+	}
+
+	/**
+	 * 设置对于文件名是否使用{@link #charset}编码
+	 *
+	 * @param encodefilename 对于文件名是否使用{@link #charset}编码
+	 * @since 5.7.16
+	 */
+	public void setEncodefilename(boolean encodefilename) {
+		this.encodefilename = encodefilename;
+	}
+
 	/**
 	 * 是否使用 STARTTLS安全连接，STARTTLS是对纯文本通信协议的扩展。它将纯文本连接升级为加密连接（TLS或SSL）， 而不是使用一个单独的加密通信端口。
 	 *
diff --git a/hutool-extra/src/test/resources/config/mail.setting b/hutool-extra/src/test/resources/config/mail.setting
index a7aa08342..f9a9cf720 100644
--- a/hutool-extra/src/test/resources/config/mail.setting
+++ b/hutool-extra/src/test/resources/config/mail.setting
@@ -20,3 +20,7 @@ starttlsEnable = true
 sslEnable = true
 # 调试模式
 debug = true
+# 对于超长参数是否切分为多份，默认为false（国内邮箱附件不支持切分的附件名）
+splitlongparameters = false
+# 是否编码附件文件名（默认true）
+encodefilename = true
diff --git a/hutool-http/src/test/java/cn/hutool/http/HttpUtilTest.java b/hutool-http/src/test/java/cn/hutool/http/HttpUtilTest.java
index e829d7752..b89e7ea99 100644
--- a/hutool-http/src/test/java/cn/hutool/http/HttpUtilTest.java
+++ b/hutool-http/src/test/java/cn/hutool/http/HttpUtilTest.java
@@ -346,4 +346,5 @@ public class HttpUtilTest {
 				.execute().body();
 		Console.log(body);
 	}
+
 }